• Python Basics
  • Interview Questions
  • Python Quiz
  • Popular Packages
  • Python Projects
  • Practice Python
  • AI With Python
  • Learn Python3
  • Python Automation
  • Python Web Dev
  • DSA with Python
  • Python OOPs
  • Dictionaries
  • Python Operators
  • Precedence and Associativity of Operators in Python
  • Python Arithmetic Operators
  • Difference between / vs. // operator in Python
  • Python - Star or Asterisk operator ( * )
  • What does the Double Star operator mean in Python?
  • Division Operators in Python
  • Modulo operator (%) in Python
  • Python Logical Operators
  • Python OR Operator
  • Difference between 'and' and '&' in Python
  • not Operator in Python | Boolean Logic
  • Ternary Operator in Python
  • Python Bitwise Operators

Python Assignment Operators

Assignment operators in python.

  • Walrus Operator in Python 3.8
  • Increment += and Decrement -= Assignment Operators in Python
  • Merging and Updating Dictionary Operators in Python 3.9
  • New '=' Operator in Python3.8 f-string

Python Relational Operators

  • Comparison Operators in Python
  • Python NOT EQUAL operator
  • Difference between == and is operator in Python
  • Chaining comparison operators in Python
  • Python Membership and Identity Operators
  • Difference between != and is not operator in Python

The Python Operators are used to perform operations on values and variables. These are the special symbols that carry out arithmetic, logical, and bitwise computations. The value the operator operates on is known as the Operand. Here, we will cover Different Assignment operators in Python .

Here are the Assignment Operators in Python with examples.

Assignment Operator

Assignment Operators are used to assign values to variables. This operator is used to assign the value of the right side of the expression to the left side operand.

Addition Assignment Operator

The Addition Assignment Operator is used to add the right-hand side operand with the left-hand side operand and then assigning the result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the addition assignment operator which will first perform the addition operation and then assign the result to the variable on the left-hand side.

S ubtraction Assignment Operator

The Subtraction Assignment Operator is used to subtract the right-hand side operand from the left-hand side operand and then assigning the result to the left-hand side operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the subtraction assignment operator which will first perform the subtraction operation and then assign the result to the variable on the left-hand side.

M ultiplication Assignment Operator

The Multiplication Assignment Operator is used to multiply the right-hand side operand with the left-hand side operand and then assigning the result to the left-hand side operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the multiplication assignment operator which will first perform the multiplication operation and then assign the result to the variable on the left-hand side.

D ivision Assignment Operator

The Division Assignment Operator is used to divide the left-hand side operand with the right-hand side operand and then assigning the result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the division assignment operator which will first perform the division operation and then assign the result to the variable on the left-hand side.

M odulus Assignment Operator

The Modulus Assignment Operator is used to take the modulus, that is, it first divides the operands and then takes the remainder and assigns it to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the modulus assignment operator which will first perform the modulus operation and then assign the result to the variable on the left-hand side.

F loor Division Assignment Operator

The Floor Division Assignment Operator is used to divide the left operand with the right operand and then assigs the result(floor value) to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the floor division assignment operator which will first perform the floor division operation and then assign the result to the variable on the left-hand side.

Exponentiation Assignment Operator

The Exponentiation Assignment Operator is used to calculate the exponent(raise power) value using operands and then assigning the result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the exponentiation assignment operator which will first perform exponent operation and then assign the result to the variable on the left-hand side.

Bitwise AND Assignment Operator

The Bitwise AND Assignment Operator is used to perform Bitwise AND operation on both operands and then assigning the result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the bitwise AND assignment operator which will first perform Bitwise AND operation and then assign the result to the variable on the left-hand side.

Bitwise OR Assignment Operator

The Bitwise OR Assignment Operator is used to perform Bitwise OR operation on the operands and then assigning result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the bitwise OR assignment operator which will first perform bitwise OR operation and then assign the result to the variable on the left-hand side.

Bitwise XOR Assignment Operator 

The Bitwise XOR Assignment Operator is used to perform Bitwise XOR operation on the operands and then assigning result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the bitwise XOR assignment operator which will first perform bitwise XOR operation and then assign the result to the variable on the left-hand side.

Bitwise Right Shift Assignment Operator

The Bitwise Right Shift Assignment Operator is used to perform Bitwise Right Shift Operation on the operands and then assign result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the bitwise right shift assignment operator which will first perform bitwise right shift operation and then assign the result to the variable on the left-hand side.

Bitwise Left Shift Assignment Operator

The Bitwise Left Shift Assignment Operator is used to perform Bitwise Left Shift Opertator on the operands and then assign result to the left operand.

Example: In this code we have two variables ‘a’ and ‘b’ and assigned them with some integer value. Then we have used the bitwise left shift assignment operator which will first perform bitwise left shift operation and then assign the result to the variable on the left-hand side.

Walrus Operator

The Walrus Operator in Python is a new assignment operator which is introduced in Python version 3.8 and higher. This operator is used to assign a value to a variable within an expression.

Example: In this code, we have a Python list of integers. We have used Python Walrus assignment operator within the Python while loop . The operator will solve the expression on the right-hand side and assign the value to the left-hand side operand ‘x’ and then execute the remaining code.

Please Login to comment...

Similar reads.

author

  • Python-Operators

Improve your Coding Skills with Practice

 alt=

What kind of Experience do you want to share?

Python Tutorial

File handling, python modules, python numpy, python pandas, python matplotlib, python scipy, machine learning, python mysql, python mongodb, python reference, module reference, python how to, python examples, python assignment operators.

Assignment operators are used to assign values to variables:

Related Pages

Get Certified

COLOR PICKER

colorpicker

Contact Sales

If you want to use W3Schools services as an educational institution, team or enterprise, send us an e-mail: [email protected]

Report Error

If you want to report an error, or if you want to make a suggestion, send us an e-mail: [email protected]

Top Tutorials

Top references, top examples, get certified.

Python Tutorial

  • Python Basics
  • Python - Home
  • Python - Overview
  • Python - History
  • Python - Features
  • Python vs C++
  • Python - Hello World Program
  • Python - Application Areas
  • Python - Interpreter
  • Python - Environment Setup
  • Python - Virtual Environment
  • Python - Basic Syntax
  • Python - Variables
  • Python - Data Types
  • Python - Type Casting
  • Python - Unicode System
  • Python - Literals
  • Python - Operators
  • Python - Arithmetic Operators
  • Python - Comparison Operators

Python - Assignment Operators

  • Python - Logical Operators
  • Python - Bitwise Operators
  • Python - Membership Operators
  • Python - Identity Operators
  • Python - Operator Precedence
  • Python - Comments
  • Python - User Input
  • Python - Numbers
  • Python - Booleans
  • Python Control Statements
  • Python - Control Flow
  • Python - Decision Making
  • Python - If Statement
  • Python - If else
  • Python - Nested If
  • Python - Match-Case Statement
  • Python - Loops
  • Python - for Loops
  • Python - for-else Loops
  • Python - While Loops
  • Python - break Statement
  • Python - continue Statement
  • Python - pass Statement
  • Python - Nested Loops
  • Python Functions & Modules
  • Python - Functions
  • Python - Default Arguments
  • Python - Keyword Arguments
  • Python - Keyword-Only Arguments
  • Python - Positional Arguments
  • Python - Positional-Only Arguments
  • Python - Arbitrary Arguments
  • Python - Variables Scope
  • Python - Function Annotations
  • Python - Modules
  • Python - Built in Functions
  • Python Strings
  • Python - Strings
  • Python - Slicing Strings
  • Python - Modify Strings
  • Python - String Concatenation
  • Python - String Formatting
  • Python - Escape Characters
  • Python - String Methods
  • Python - String Exercises
  • Python Lists
  • Python - Lists
  • Python - Access List Items
  • Python - Change List Items
  • Python - Add List Items
  • Python - Remove List Items
  • Python - Loop Lists
  • Python - List Comprehension
  • Python - Sort Lists
  • Python - Copy Lists
  • Python - Join Lists
  • Python - List Methods
  • Python - List Exercises
  • Python Tuples
  • Python - Tuples
  • Python - Access Tuple Items
  • Python - Update Tuples
  • Python - Unpack Tuples
  • Python - Loop Tuples
  • Python - Join Tuples
  • Python - Tuple Methods
  • Python - Tuple Exercises
  • Python Sets
  • Python - Sets
  • Python - Access Set Items
  • Python - Add Set Items
  • Python - Remove Set Items
  • Python - Loop Sets
  • Python - Join Sets
  • Python - Copy Sets
  • Python - Set Operators
  • Python - Set Methods
  • Python - Set Exercises
  • Python Dictionaries
  • Python - Dictionaries
  • Python - Access Dictionary Items
  • Python - Change Dictionary Items
  • Python - Add Dictionary Items
  • Python - Remove Dictionary Items
  • Python - Dictionary View Objects
  • Python - Loop Dictionaries
  • Python - Copy Dictionaries
  • Python - Nested Dictionaries
  • Python - Dictionary Methods
  • Python - Dictionary Exercises
  • Python Arrays
  • Python - Arrays
  • Python - Access Array Items
  • Python - Add Array Items
  • Python - Remove Array Items
  • Python - Loop Arrays
  • Python - Copy Arrays
  • Python - Reverse Arrays
  • Python - Sort Arrays
  • Python - Join Arrays
  • Python - Array Methods
  • Python - Array Exercises
  • Python File Handling
  • Python - File Handling
  • Python - Write to File
  • Python - Read Files
  • Python - Renaming and Deleting Files
  • Python - Directories
  • Python - File Methods
  • Python - OS File/Directory Methods
  • Object Oriented Programming
  • Python - OOPs Concepts
  • Python - Object & Classes
  • Python - Class Attributes
  • Python - Class Methods
  • Python - Static Methods
  • Python - Constructors
  • Python - Access Modifiers
  • Python - Inheritance
  • Python - Polymorphism
  • Python - Method Overriding
  • Python - Method Overloading
  • Python - Dynamic Binding
  • Python - Dynamic Typing
  • Python - Abstraction
  • Python - Encapsulation
  • Python - Interfaces
  • Python - Packages
  • Python - Inner Classes
  • Python - Anonymous Class and Objects
  • Python - Singleton Class
  • Python - Wrapper Classes
  • Python - Enums
  • Python - Reflection
  • Python Errors & Exceptions
  • Python - Syntax Errors
  • Python - Exceptions
  • Python - try-except Block
  • Python - try-finally Block
  • Python - Raising Exceptions
  • Python - Exception Chaining
  • Python - Nested try Block
  • Python - User-defined Exception
  • Python - Logging
  • Python - Assertions
  • Python - Built-in Exceptions
  • Python Multithreading
  • Python - Multithreading
  • Python - Thread Life Cycle
  • Python - Creating a Thread
  • Python - Starting a Thread
  • Python - Joining Threads
  • Python - Naming Thread
  • Python - Thread Scheduling
  • Python - Thread Pools
  • Python - Main Thread
  • Python - Thread Priority
  • Python - Daemon Threads
  • Python - Synchronizing Threads
  • Python Synchronization
  • Python - Inter-thread Communication
  • Python - Thread Deadlock
  • Python - Interrupting a Thread
  • Python Networking
  • Python - Networking
  • Python - Socket Programming
  • Python - URL Processing
  • Python - Generics
  • Python Libraries
  • NumPy Tutorial
  • Pandas Tutorial
  • SciPy Tutorial
  • Matplotlib Tutorial
  • Django Tutorial
  • OpenCV Tutorial
  • Python Miscellenous
  • Python - Date & Time
  • Python - Maths
  • Python - Iterators
  • Python - Generators
  • Python - Closures
  • Python - Decorators
  • Python - Recursion
  • Python - Reg Expressions
  • Python - PIP
  • Python - Database Access
  • Python - Weak References
  • Python - Serialization
  • Python - Templating
  • Python - Output Formatting
  • Python - Performance Measurement
  • Python - Data Compression
  • Python - CGI Programming
  • Python - XML Processing
  • Python - GUI Programming
  • Python - Command-Line Arguments
  • Python - Docstrings
  • Python - JSON
  • Python - Sending Email
  • Python - Further Extensions
  • Python - Tools/Utilities
  • Python - GUIs
  • Python Questions and Answers
  • Python Useful Resources
  • Python Compiler
  • NumPy Compiler
  • Matplotlib Compiler
  • SciPy Compiler
  • Python - Programming Examples
  • Python - Quick Guide
  • Python - Useful Resources
  • Python - Discussion
  • Selected Reading
  • UPSC IAS Exams Notes
  • Developer's Best Practices
  • Questions and Answers
  • Effective Resume Writing
  • HR Interview Questions
  • Computer Glossary

Python Assignment Operator

The = (equal to) symbol is defined as assignment operator in Python. The value of Python expression on its right is assigned to a single variable on its left. The = symbol as in programming in general (and Python in particular) should not be confused with its usage in Mathematics, where it states that the expressions on the either side of the symbol are equal.

Example of Assignment Operator in Python

Consider following Python statements −

At the first instance, at least for somebody new to programming but who knows maths, the statement "a=a+b" looks strange. How could a be equal to "a+b"? However, it needs to be reemphasized that the = symbol is an assignment operator here and not used to show the equality of LHS and RHS.

Because it is an assignment, the expression on right evaluates to 15, the value is assigned to a.

In the statement "a+=b", the two operators "+" and "=" can be combined in a "+=" operator. It is called as add and assign operator. In a single statement, it performs addition of two operands "a" and "b", and result is assigned to operand on left, i.e., "a".

Augmented Assignment Operators in Python

In addition to the simple assignment operator, Python provides few more assignment operators for advanced use. They are called cumulative or augmented assignment operators. In this chapter, we shall learn to use augmented assignment operators defined in Python.

Python has the augmented assignment operators for all arithmetic and comparison operators.

Python augmented assignment operators combines addition and assignment in one statement. Since Python supports mixed arithmetic, the two operands may be of different types. However, the type of left operand changes to the operand of on right, if it is wider.

The += operator is an augmented operator. It is also called cumulative addition operator, as it adds "b" in "a" and assigns the result back to a variable.

The following are the augmented assignment operators in Python:

  • Augmented Addition Operator
  • Augmented Subtraction Operator
  • Augmented Multiplication Operator
  • Augmented Division Operator
  • Augmented Modulus Operator
  • Augmented Exponent Operator
  • Augmented Floor division Operator

Augmented Addition Operator (+=)

Following examples will help in understanding how the "+=" operator works −

It will produce the following output −

Augmented Subtraction Operator (-=)

Use -= symbol to perform subtract and assign operations in a single statement. The "a-=b" statement performs "a=a-b" assignment. Operands may be of any number type. Python performs implicit type casting on the object which is narrower in size.

Augmented Multiplication Operator (*=)

The "*=" operator works on similar principle. "a*=b" performs multiply and assign operations, and is equivalent to "a=a*b". In case of augmented multiplication of two complex numbers, the rule of multiplication as discussed in the previous chapter is applicable.

Augmented Division Operator (/=)

The combination symbol "/=" acts as divide and assignment operator, hence "a/=b" is equivalent to "a=a/b". The division operation of int or float operands is float. Division of two complex numbers returns a complex number. Given below are examples of augmented division operator.

Augmented Modulus Operator (%=)

To perform modulus and assignment operation in a single statement, use the %= operator. Like the mod operator, its augmented version also is not supported for complex number.

Augmented Exponent Operator (**=)

The "**=" operator results in computation of "a" raised to "b", and assigning the value back to "a". Given below are some examples −

Augmented Floor division Operator (//=)

For performing floor division and assignment in a single statement, use the "//=" operator. "a//=b" is equivalent to "a=a//b". This operator cannot be used with complex numbers.

To Continue Learning Please Login

Learn Python practically and Get Certified .

Popular Tutorials

Popular examples, reference materials, learn python interactively, python introduction.

  • Get Started With Python
  • Your First Python Program
  • Python Comments

Python Fundamentals

  • Python Variables and Literals
  • Python Type Conversion
  • Python Basic Input and Output

Python Operators

Python flow control.

Python if...else Statement

  • Python for Loop
  • Python while Loop
  • Python break and continue
  • Python pass Statement

Python Data types

  • Python Numbers, Type Conversion and Mathematics
  • Python List
  • Python Tuple
  • Python Sets
  • Python Dictionary
  • Python Functions
  • Python Function Arguments
  • Python Variable Scope
  • Python Global Keyword
  • Python Recursion
  • Python Modules
  • Python Package
  • Python Main function

Python Files

  • Python Directory and Files Management
  • Python CSV: Read and Write CSV files
  • Reading CSV files in Python
  • Writing CSV files in Python
  • Python Exception Handling
  • Python Exceptions
  • Python Custom Exceptions

Python Object & Class

  • Python Objects and Classes
  • Python Inheritance
  • Python Multiple Inheritance
  • Polymorphism in Python

Python Operator Overloading

Python Advanced Topics

  • List comprehension
  • Python Lambda/Anonymous Function
  • Python Iterators
  • Python Generators
  • Python Namespace and Scope
  • Python Closures
  • Python Decorators
  • Python @property decorator
  • Python RegEx

Python Date and Time

  • Python datetime
  • Python strftime()
  • Python strptime()
  • How to get current date and time in Python?
  • Python Get Current Time
  • Python timestamp to datetime and vice-versa
  • Python time Module
  • Python sleep()

Additional Topic

Precedence and Associativity of Operators in Python

  • Python Keywords and Identifiers
  • Python Asserts
  • Python Json
  • Python *args and **kwargs

Python Tutorials

Python 3 Tutorial

  • Python Strings
  • Python any()

Operators are special symbols that perform operations on variables and values. For example,

Here, + is an operator that adds two numbers: 5 and 6 .

  • Types of Python Operators

Here's a list of different types of Python operators that we will learn in this tutorial.

  • Arithmetic Operators
  • Assignment Operators
  • Comparison Operators
  • Logical Operators
  • Bitwise Operators
  • Special Operators

1. Python Arithmetic Operators

Arithmetic operators are used to perform mathematical operations like addition, subtraction, multiplication, etc. For example,

Here, - is an arithmetic operator that subtracts two values or variables.

Example 1: Arithmetic Operators in Python

In the above example, we have used multiple arithmetic operators,

  • + to add a and b
  • - to subtract b from a
  • * to multiply a and b
  • / to divide a by b
  • // to floor divide a by b
  • % to get the remainder
  • ** to get a to the power b

2. Python Assignment Operators

Assignment operators are used to assign values to variables. For example,

Here, = is an assignment operator that assigns 5 to x .

Here's a list of different assignment operators available in Python.

Example 2: Assignment Operators

Here, we have used the += operator to assign the sum of a and b to a .

Similarly, we can use any other assignment operators as per our needs.

3. Python Comparison Operators

Comparison operators compare two values/variables and return a boolean result: True or False . For example,

Here, the > comparison operator is used to compare whether a is greater than b or not.

Example 3: Comparison Operators

Note: Comparison operators are used in decision-making and loops . We'll discuss more of the comparison operator and decision-making in later tutorials.

4. Python Logical Operators

Logical operators are used to check whether an expression is True or False . They are used in decision-making. For example,

Here, and is the logical operator AND . Since both a > 2 and b >= 6 are True , the result is True .

Example 4: Logical Operators

Note : Here is the truth table for these logical operators.

5. Python Bitwise operators

Bitwise operators act on operands as if they were strings of binary digits. They operate bit by bit, hence the name.

For example, 2 is 10 in binary, and 7 is 111 .

In the table below: Let x = 10 ( 0000 1010 in binary) and y = 4 ( 0000 0100 in binary)

6. Python Special operators

Python language offers some special types of operators like the identity operator and the membership operator. They are described below with examples.

  • Identity operators

In Python, is and is not are used to check if two values are located at the same memory location.

It's important to note that having two variables with equal values doesn't necessarily mean they are identical.

Example 4: Identity operators in Python

Here, we see that x1 and y1 are integers of the same values, so they are equal as well as identical. The same is the case with x2 and y2 (strings).

But x3 and y3 are lists. They are equal but not identical. It is because the interpreter locates them separately in memory, although they are equal.

  • Membership operators

In Python, in and not in are the membership operators. They are used to test whether a value or variable is found in a sequence ( string , list , tuple , set and dictionary ).

In a dictionary, we can only test for the presence of a key, not the value.

Example 5: Membership operators in Python

Here, 'H' is in message , but 'hello' is not present in message (remember, Python is case-sensitive).

Similarly, 1 is key, and 'a' is the value in dictionary dict1 . Hence, 'a' in y returns False .

  • Precedence and Associativity of operators in Python

Table of Contents

  • Introduction
  • Python Arithmetic Operators
  • Python Assignment Operators
  • Python Comparison Operators
  • Python Logical Operators
  • Python Bitwise operators
  • Python Special operators

Video: Operators in Python

Sorry about that.

Related Tutorials

Python Tutorial

logo

Python Assignment Operators

In Python, an assignment operator is used to assign a value to a variable. The assignment operator is a single equals sign (=). Here is an example of using the assignment operator to assign a value to a variable:

In this example, the variable x is assigned the value 5.

There are also several compound assignment operators in Python, which are used to perform an operation and assign the result to a variable in a single step. These operators include:

  • +=: adds the right operand to the left operand and assigns the result to the left operand
  • -=: subtracts the right operand from the left operand and assigns the result to the left operand
  • *=: multiplies the left operand by the right operand and assigns the result to the left operand
  • /=: divides the left operand by the right operand and assigns the result to the left operand
  • %=: calculates the remainder of the left operand divided by the right operand and assigns the result to the left operand
  • //=: divides the left operand by the right operand and assigns the result as an integer to the left operand
  • **=: raises the left operand to the power of the right operand and assigns the result to the left operand

Here are some examples of using compound assignment operators:

Python Assignment Operators

Lesson Contents

Python assignment operators are one of the operator types and assign values to variables . We use arithmetic operators here in combination with a variable.

Let’s take a look at some examples.

Operator Assignment (=)

This is the most basic assignment operator and we used it before in the lessons about lists , tuples , and dictionaries .  For example, we can assign a value (integer) to a variable:

Operator Addition (+=)

We can add a number to our variable like this:

Using the above operator is the same as doing this:

The += operator is shorter to write but the end result is the same.

Operator Subtraction (-=)

We can also subtract a value. For example:

Using this operator is the same as doing this:

Operator Multiplication (*=)

We can also use multiplication. We’ll multiply our variable by 4:

Which is similar to:

Operator Division (/=)

Let’s try the divide operator:

This is the same as:

Operator Modulus (%=)

We can also calculate the modulus. How about this:

This is the same as doing it like this:

Operator Exponentiation (**=)

How about exponentiation? Let’s give it a try:

Which is the same as doing it like this:

Operator Floor Division (//=)

The last one, floor division:

You have now learned how to use the Python assignment operators to assign values to variables and how you can use them with arithmetic operators . I hope you enjoyed this lesson. If you have any questions, please leave a comment.

Ask a question or start a discussion by visiting our Community Forum

Assignment Operators

This lesson showcases Python's various assignment operators and their purpose.

Assigning Values

  • The Other Operators

This is a category of operators which is used to assign values to a variable. The = operator is an assignment operator, but not the only one.

Here’s a list of all the assignment operators supported in Python:

Let’s go through a few examples to see how values are assigned to variables.

Variables are mutable , so we can change their values whenever we want!

Get hands-on with 1200+ tech skills courses.

Python Operators: Arithmetic, Assignment, Comparison, Logical, Identity, Membership, Bitwise

Operators are special symbols that perform some operation on operands and returns the result. For example, 5 + 6 is an expression where + is an operator that performs arithmetic add operation on numeric left operand 5 and the right side operand 6 and returns a sum of two operands as a result.

Python includes the operator module that includes underlying methods for each operator. For example, the + operator calls the operator.add(a,b) method.

Above, expression 5 + 6 is equivalent to the expression operator.add(5, 6) and operator.__add__(5, 6) . Many function names are those used for special methods, without the double underscores (dunder methods). For backward compatibility, many of these have functions with the double underscores kept.

Python includes the following categories of operators:

Arithmetic Operators

Assignment operators, comparison operators, logical operators, identity operators, membership test operators, bitwise operators.

Arithmetic operators perform the common mathematical operation on the numeric operands.

The arithmetic operators return the type of result depends on the type of operands, as below.

  • If either operand is a complex number, the result is converted to complex;
  • If either operand is a floating point number, the result is converted to floating point;
  • If both operands are integers, then the result is an integer and no conversion is needed.

The following table lists all the arithmetic operators in Python:

The assignment operators are used to assign values to variables. The following table lists all the arithmetic operators in Python:

The comparison operators compare two operands and return a boolean either True or False. The following table lists comparison operators in Python.

The logical operators are used to combine two boolean expressions. The logical operations are generally applicable to all objects, and support truth tests, identity tests, and boolean operations.

The identity operators check whether the two objects have the same id value e.i. both the objects point to the same memory location.

The membership test operators in and not in test whether the sequence has a given item or not. For the string and bytes types, x in y is True if and only if x is a substring of y .

Bitwise operators perform operations on binary operands.

  • Compare strings in Python
  • Convert file data to list
  • Convert User Input to a Number
  • Convert String to Datetime in Python
  • How to call external commands in Python?
  • How to count the occurrences of a list item?
  • How to flatten list in Python?
  • How to merge dictionaries in Python?
  • How to pass value by reference in Python?
  • Remove duplicate items from list in Python
  • More Python articles

all assignment operators in python program

We are a team of passionate developers, educators, and technology enthusiasts who, with their combined expertise and experience, create in -depth, comprehensive, and easy to understand tutorials.We focus on a blend of theoretical explanations and practical examples to encourages hands - on learning. Visit About Us page for more information.

  • Python Questions & Answers
  • Python Skill Test
  • Python Latest Articles

codingzap_logo_1-768x768

  • Case Studies
  • Our Pricing
  • Do my Programming Homework
  • Java Homework Help
  • HTML Homework Help
  • Do my computer science homework
  • C++ Homework Help
  • C Homework Help
  • Python Assignment Help
  • Android Assignment help
  • Database Homework Help
  • PHP Assignment Help
  • JavaScript Assignment Help
  • R Assignment Help
  • Node.Js Homework Help
  • Data Structures Assignment Help
  • Machine Learning Assignment Help
  • MATLAB Assignment Help
  • C Sharp Assignment Help
  • Operating System Assignment Help
  • Assembly Language Assignment Help
  • Scala Assignment Help
  • Visual Basic Assignment Help
  • Live Java Tutoring
  • Python Tutoring
  • Our Experts
  • Testimonials
  • Submit Your Assignment

all assignment operators in python program

Assignment Operators in Python

Assignment Operators in Python

In this article, we will learn about all the “ Assignment Operators in Python ” with examples of each.  Assignment operators in Python are essential tools for manipulating and assigning values to variables. These operators not only let you store data in variables but also perform various operations simultaneously. Understanding these operators is crucial for efficient Python programming, as they streamline code while making it more readable and maintainable. If you encounter any challenges in grasping these operators, don’t hesitate to seek Python help from the experts at CodingZap.

What Are Operators and Operands?

Operators can be understood as the mathematical symbols we have seen since childhood, like the +, -, *, / =. They are used to perform mathematical, logical or bitwise operations in a programming language. 

Operands are the values or variables on which operators act. For example, “+” will add the values of two operands, and similarly “*” will multiply the values of the 2 operands. 

In the expression “a+b”,  “+” is the operator and “a” and “b” are the operands. 

What Is Assignment Operators in Python?

Python Assignment Help

Assignment operators are a fundamental concept in Python and most programming languages. They are used to assign values to variables, as well as initialize and update them. They assign the value on the right-hand side to the variable on the left.

In Python, the primary assignment operator is the “Simple assignment operator (=)”, which as the name suggests, assigns values to variables. However, Python offers a rich set of assignment operators that provide more functionality than simple assignments. These operators not only assign values but also perform specific operations at the same time, such as addition, subtraction, multiplication, division, bitwise operations, and more. 

What Are the Basics of Assignments?

First, we’ll clarify some basic rules about the assignments in Python. For this, we’ll use the simple assignment operator “=”.

A sample program using “=” is as follows:

In the above example, the value on the right-hand side is assigned to the variable on the left. We check the value assigned by printing the variable and get the expected result, i.e. 5. 

In the example above, the statement a = 5 is called an assignment statement, which assigns values to the variables. 

The syntax for an assignment statement is as follows:

As we can see, it is composed of three components:

  • The left operand of an assignment statement must always and only be a variable. 
  • Then comes the assignment operator itself.
  • The right operand can be a value, an expression or an object. 

Now that we have this rule clear let us look at the assignment operators in Python. The assignment operators allow us to create, initialise and update the variables. 

The simple assignment operator “=”

It is the primary assignment operator

Let’s look at some examples to understand the uses of the simple assignment operator:

As we can see in the above code, the simple assignment operator is used to create every variable type in Python, be it a primitive integer, string, or complex data structure. Strings are also an interesting concept in Python, if you’re interested to know how to compare strings in Python then you can check out our article.

Updating values

The assignment operators are also used to update variable values in Python. An example is as follows:

In the above example, we initialized our integer and list with initial values and printed them for reference. Then, we modified these values and printed them again to verify the changes. 

Multiple and parallel assignments

Python provides additional functionality to perform multiple and parallel assignments to variables in a single line. This reduces lines of code and complexity. Let’s understand them with an example:

In the above code, we demonstrate multiple and parallel assignments. 

We can assign the same literal value to multiple variables in multiple assignments. In the above code, the integer value 45 is assigned to all the variables a,b,c. The data type of all the variables in a multiple-assignment statement must be the same.

In parallel assignments, we can assign different values to different variables using comma-separated variables and values on either side of the assignment operator. The values are stored in the order of writing the pairs. The variable types need not be the same in parallel assignments. 

Augmented assignment operators in Python

The simple assignment operator is used to assign values to variables in Python. However, Python also supports complex assignments using which we can calculate various values and assign them to the variable in a single line. 

The basic syntax for augmented assignment operators is as follows:

The ‘$’ in the above syntax can be replaced by various operators to perform operations on operands before assigning the final value to the variable. 

Python equates the above syntax to the following expression:

We’ll understand these operators better if we directly look at their examples.  

Let’s have a look at all the augmented assignment operators in Python one at a time:

Add assignment operator “+=”

This operator adds the left and the right operands and assigns the resulting value to the variable on the left. 

An example would be

Which will equate to

It is important to note that only the value of “a” will change, whereas the value of “b” will remain the same. This is because the sum of “a” and “b” is finally stored in the variable “a”. 

Let’s look at the code and its output:

In the above code, we initialized 2 variables and added the value of the second variable to the first one using the add assignment operator. Note that the value of “a” changes, but the value of “b” remains the same. 

This operator can also be used on some data structures like lists and tuples, using which we can append values at the end of the list, as can be seen in the code above. 

Subtract assignment operator

This operator is used to subtract the right operand from the left and assign the resulting value to the variable on the left. 

A sample code is as follows:

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. Then, we subtracted the value of “b” from “a” using the subtract assignment operator. The final expression equated to “a=a-b”. At last, we printed the final values of “a” and “b”. 

Multiplication assignment operator

The multiplication assignment operator is used to multiply the right operand with the left and assign the resulting value to the variable on the left. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. Then, we multiplied the values of “a” and “b” using the multiplication assignment operator. The final expression equated to “a=a*b”. At last, we printed the final values of “a” and “b” to check the resulting values. 

Division assignment operator

The division assignment operator divides the left operand from the right and assigns the resulting value to the operand on the left. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. Then, we divided “a” by “b” using the division assignment operator. The final expression equated to “a=a/b”. At last, we printed the final values of “a” and “b”. 

Floor assignment operator

The floor assignment operator divides the operand on the left from the right and rounds the value to the greatest integer less than or equal to the resultant value. This value is then stored in the operand on the left.

Sample code is as follows:

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. Then, we divided “a” from “b” using the floor assignment operator. This operator also divides the variables in the same way as the division assignment operator but rounds off the answer to the greatest integer less than or equal to the answer. In this case, the value “16.66” was rounded off to “16”.

At last, we printed the final values of “a” and “b”. 

Modulus assignment operator

The modulus assignment operator is used to extract the remainder after dividing the operand on the left from the right. The remainder is then stored in the operand on the left.

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the modulus assignment operator to get the remainder of the division “a/b”, and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

Exponentiation assignment operator

This operator is used to calculate the exponent of the left-side operand raised to the power of the right-side operand, which is then stored in the operand on the left. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the exponentiation assignment operator to get the value of “a” raised to the power of “b”, and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

Bitwise AND assignment operator

This operator calculates the Bitwise AND value of the operands on the left and right and stores the value in the left operand. 

Sample code:

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the bitwise AND assignment operator to get the bitwise AND of “a” and “b”, and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

Bitwise OR assignment operator

This operator calculates the Bitwise OR value of the operands on the left and right and stores the value in the left operand. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the bitwise OR assignment operator to get the bitwise 

OR of “a” and “b”, and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

Bitwise XOR assignment operator

This operator calculates the XOR of the 2 operands and stores the value in the left operand. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the bitwise XOR assignment operator to get the bitwise XOR of “a” and “b” and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

Bitwise Left Shift assignment operator

This operator left-shifts the bits of the operand on the left by the units as declared by the operand on the right and stores the value in the left operand. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the bitwise left shift assignment operator to left shift the bits of “a” by “b” units and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

Bitwise Right Shift assignment operator

This operator right-shifts the bits of the operand on the left by the units as declared by the operand on the right, and stores the value in the left operand. 

In the above code, we initialized the 2 variables “a” and “b” and printed their values for reference. We then used the bitwise right shift assignment operator to right shift the bits of “a” by “b” units, and store the resulting value in “a”. At last, we printed the final values of “a” and “b”. 

In this article, we learned about the assignment operators in Python. The primary assignment operator is the simple assignment operator (“=”).

We then learned that Python supports more complex assignment operators that can be used to calculate values in place. 

The assignment operators can be used to calculate mathematical, logical, and bitwise operations. 

We also saw a consistent property of all the assignment operators, in which they calculated the expression on the right and assigned the resulting value to the variable on the left. 

There are many reasons why students look for assignment help online like difficulty in understanding the assignment, time limitation, etc. So, if you’re also looking then you can always hire CodinngZap experts.

Hire Python Experts now

Sounetra Ghosal

Leave a comment cancel reply.

Your email address will not be published. Required fields are marked *

CodingZap white Logo

CodingZap is founded back in 2015 with a mindset to provide genuine programming help to students across the globe. We cater to a broad range of programming homework help services to students and techies who are struggling with their code.

Programming Help Expertise

Contact us now.

  • HQ USA: 920 Beach Park Blvd, Foster City, USA
  • +1 (332) 895-6153
  • [email protected]

CodingZap accepts all major Debit and Credit cards payment.

Important Links

Copyright 2015-2024 CodingZap Technologies Private Limited- All rights reserved.

  • Read Tutorial
  • Watch Guide Video

If that is about as clear as mud don't worry we're going to walk through a number of examples. And one very nice thing about the syntax for assignment operators is that it is nearly identical to a standard type of operator. So if you memorize the list of all the python operators then you're going to be able to use each one of these assignment operators quite easily.

The very first thing I'm going to do is let's first make sure that we can print out the total. So right here we have a total and it's an integer that equals 100. Now if we wanted to add say 10 to 100 how would we go about doing that? We could reassign the value total and we could say total and then just add 10. So let's see if this works right here. I'm going to run it and you can see we have a hundred and ten. So that works.

large

However, whenever you find yourself performing this type of calculation what you can do is use an assignment operator. And so the syntax for that is going to get rid of everything here in the middle and say plus equals and then whatever value. In this case I want to add onto it.

So you can see we have our operator and then right afterward you have an equal sign. And this is going to do is exactly like what we had before. So if I run this again you can see total is a hundred and ten

large

I'm going to just so you have a reference in the show notes I'm going to say that total equals total plus 10. This is exactly the same as what we're doing right here we're simply using assignment in order to do it.

I'm going to quickly go through each one of the other elements that you can use assignment for. And if you go back and you reference the show notes or your own notes for whenever you kept track of all of the different operators you're going to notice a trend. And that is because they're all exactly the same. So here if I want to subtract 10 from the total I can simply use the subtraction operator here run it again. And now you can see we have 90. Now don't be confused because we only temporarily change the value to 1 10. So when I commented this out and I ran it from scratch it took the total and it subtracted 10 from that total and that's what got printed out.

large

I'm going to copy this and the next one down the line is going to be multiplication. So in this case I'm going to say multiply with the asterisk the total and I'm just going to say times two just so we can see exactly what the value is going to be. And now we can see that's 200 which makes sense.

large

So we've taken total we have multiplied it by two and we have piped the entire thing into the total variable. So far so good. As you may have guessed next when we're going to do is division. So now I'm going to say total and then we're going to perform this division assignment and we're going to say divide this by 10 run it and you can see it gives us the value and it converts it to a float of ten point zero.

large

Now if this is starting to get a little bit much. Let's take a quick pause and see exactly what this is doing. Remember that all we're doing here is it's a shortcut. You could still perform it the same way we have in number 3 I could say total is equal to the total divided by 10. And if I run this you'll see we get ten point zero. And let's see what this warning is it says redefinition of total type from int to float. So we don't have to worry about this and this for if you're building Python programs you're very rarely ever going to see the syntax and it's because we have this assignment operator right here. So that is for division. And we also have the ability to use floor division as well. So if I run this you're going to see it's 10. But one thing you may notice is it's 10 it's not ten point zero. So remember that our floor division returns an integer it doesn't return a floating-point number. So if that is what you want then you can perform that task just like we did there.

Next one on the list is our exponents. I'm going to say the total and we're going to say we're going to assign that to the total squared. So going to run this and we get ten thousand. Just like you'd expect. And we have one more which is the modulus operator. So here remember it is the percent equals 2. And this is going to return zero because 100 is even if we changed 100 to be 101. This is going to return one because remember the typical purpose of the modulus operator is to let you know if you're working with an event or an odd value.

large

Now with all this being said, I wanted to show you every different option that you could use the assignment operator on. But I want to say that the most common way that you're going to use this or the most common one is going to be this one right here where we're adding or subtracting. So those are going to be the two most common. And what usually you're going to use that for is when you're incrementing or decrementing values so a very common way to do this would actually be like we have our total right here. So we have a total of 100 and you could imagine it being a shopping cart and it's 100 dollars and you could say product 2 and set this equal to 120. And then if I say product 3 and set this equal to 10. And so what I could do here is I could say total plus equals product to and then we could take the value and say product 3 and now if I run this you can see the value is 230.

large

So that's a very common way whenever you want to generate a sum you can use this type of syntax which is much faster and it's also going to be a more pythonic way it's going to be the way you're going to see in standard Python programs whenever you're wanting to generate a sum and then reset and reassign the value.

So in review, that is how you can use assignment operators in Python.

devCamp does not support ancient browsers. Install a modern version for best experience.

PrepBytes Blog

ONE-STOP RESOURCE FOR EVERYTHING RELATED TO CODING

Sign in to your account

Forgot your password?

Login via OTP

We will send you an one time password on your mobile number

An OTP has been sent to your mobile number please verify it below

Register with PrepBytes

Assignment operator in python.

' src=

Last Updated on June 8, 2023 by Prepbytes

all assignment operators in python program

To fully comprehend the assignment operators in Python, it is important to have a basic understanding of what operators are. Operators are utilized to carry out a variety of operations, including mathematical, bitwise, and logical operations, among others, by connecting operands. Operands are the values that are acted upon by operators. In Python, the assignment operator is used to assign a value to a variable. The assignment operator is represented by the equals sign (=), and it is the most commonly used operator in Python. In this article, we will explore the assignment operator in Python, how it works, and its different types.

What is an Assignment Operator in Python?

The assignment operator in Python is used to assign a value to a variable. The assignment operator is represented by the equals sign (=), and it is used to assign a value to a variable. When an assignment operator is used, the value on the right-hand side is assigned to the variable on the left-hand side. This is a fundamental operation in programming, as it allows developers to store data in variables that can be used throughout their code.

For example, consider the following line of code:

Explanation: In this case, the value 10 is assigned to the variable a using the assignment operator. The variable a now holds the value 10, and this value can be used in other parts of the code. This simple example illustrates the basic usage and importance of assignment operators in Python programming.

Types of Assignment Operator in Python

There are several types of assignment operator in Python that are used to perform different operations. Let’s explore each type of assignment operator in Python in detail with the help of some code examples.

1. Simple Assignment Operator (=)

The simple assignment operator is the most commonly used operator in Python. It is used to assign a value to a variable. The syntax for the simple assignment operator is:

Here, the value on the right-hand side of the equals sign is assigned to the variable on the left-hand side. For example

Explanation: In this case, the value 25 is assigned to the variable a using the simple assignment operator. The variable a now holds the value 25.

2. Addition Assignment Operator (+=)

The addition assignment operator is used to add a value to a variable and store the result in the same variable. The syntax for the addition assignment operator is:

Here, the value on the right-hand side is added to the variable on the left-hand side, and the result is stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is incremented by 5 using the addition assignment operator. The result, 15, is then printed to the console.

3. Subtraction Assignment Operator (-=)

The subtraction assignment operator is used to subtract a value from a variable and store the result in the same variable. The syntax for the subtraction assignment operator is

Here, the value on the right-hand side is subtracted from the variable on the left-hand side, and the result is stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is decremented by 5 using the subtraction assignment operator. The result, 5, is then printed to the console.

4. Multiplication Assignment Operator (*=)

The multiplication assignment operator is used to multiply a variable by a value and store the result in the same variable. The syntax for the multiplication assignment operator is:

Here, the value on the right-hand side is multiplied by the variable on the left-hand side, and the result is stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is multiplied by 5 using the multiplication assignment operator. The result, 50, is then printed to the console.

5. Division Assignment Operator (/=)

The division assignment operator is used to divide a variable by a value and store the result in the same variable. The syntax for the division assignment operator is:

Here, the variable on the left-hand side is divided by the value on the right-hand side, and the result is stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is divided by 5 using the division assignment operator. The result, 2.0, is then printed to the console.

6. Modulus Assignment Operator (%=)

The modulus assignment operator is used to find the remainder of the division of a variable by a value and store the result in the same variable. The syntax for the modulus assignment operator is

Here, the variable on the left-hand side is divided by the value on the right-hand side, and the remainder is stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is divided by 3 using the modulus assignment operator. The remainder, 1, is then printed to the console.

7. Floor Division Assignment Operator (//=)

The floor division assignment operator is used to divide a variable by a value and round the result down to the nearest integer, and store the result in the same variable. The syntax for the floor division assignment operator is:

Here, the variable on the left-hand side is divided by the value on the right-hand side, and the result is rounded down to the nearest integer. The rounded result is then stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is divided by 3 using the floor division assignment operator. The result, 3, is then printed to the console.

8. Exponentiation Assignment Operator (**=)

The exponentiation assignment operator is used to raise a variable to the power of a value and store the result in the same variable. The syntax for the exponentiation assignment operator is:

Here, the variable on the left-hand side is raised to the power of the value on the right-hand side, and the result is stored back in the variable on the left-hand side. For example

Explanation: In this case, the value of a is raised to the power of 3 using the exponentiation assignment operator. The result, 8, is then printed to the console.

9. Bitwise AND Assignment Operator (&=)

The bitwise AND assignment operator is used to perform a bitwise AND operation on the binary representation of a variable and a value, and store the result in the same variable. The syntax for the bitwise AND assignment operator is:

Here, the variable on the left-hand side is ANDed with the value on the right-hand side using the bitwise AND operator, and the result is stored back in the variable on the left-hand side. For example,

Explanation: In this case, the value of a is ANDed with 3 using the bitwise AND assignment operator. The result, 2, is then printed to the console.

10. Bitwise OR Assignment Operator (|=)

The bitwise OR assignment operator is used to perform a bitwise OR operation on the binary representation of a variable and a value, and store the result in the same variable. The syntax for the bitwise OR assignment operator is:

Here, the variable on the left-hand side is ORed with the value on the right-hand side using the bitwise OR operator, and the result is stored back in the variable on the left-hand side. For example,

Explanation: In this case, the value of a is ORed with 3 using the bitwise OR assignment operator. The result, 7, is then printed to the console.

11. Bitwise XOR Assignment Operator (^=)

The bitwise XOR assignment operator is used to perform a bitwise XOR operation on the binary representation of a variable and a value, and store the result in the same variable. The syntax for the bitwise XOR assignment operator is:

Here, the variable on the left-hand side is XORed with the value on the right-hand side using the bitwise XOR operator, and the result are stored back in the variable on the left-hand side. For example,

Explanation: In this case, the value of a is XORed with 3 using the bitwise XOR assignment operator. The result, 5, is then printed to the console.

12. Bitwise Right Shift Assignment Operator (>>=)

The bitwise right shift assignment operator is used to shift the bits of a variable to the right by a specified number of positions, and store the result in the same variable. The syntax for the bitwise right shift assignment operator is:

Here, the variable on the left-hand side has its bits shifted to the right by the number of positions specified by the value on the right-hand side, and the result is stored back in the variable on the left-hand side. For example,

Explanation: In this case, the value of a is shifted 2 positions to the right using the bitwise right shift assignment operator. The result, 2, is then printed to the console.

13. Bitwise Left Shift Assignment Operator (<<=)

The bitwise left shift assignment operator is used to shift the bits of a variable to the left by a specified number of positions, and store the result in the same variable. The syntax for the bitwise left shift assignment operator is:

Here, the variable on the left-hand side has its bits shifted to the left by the number of positions specified by the value on the right-hand side, and the result is stored back in the variable on the left-hand side. For example,

Conclusion Assignment operator in Python is used to assign values to variables, and it comes in different types. The simple assignment operator (=) assigns a value to a variable. The augmented assignment operators (+=, -=, *=, /=, %=, &=, |=, ^=, >>=, <<=) perform a specified operation and assign the result to the same variable in one step. The modulus assignment operator (%) calculates the remainder of a division operation and assigns the result to the same variable. The bitwise assignment operators (&=, |=, ^=, >>=, <<=) perform bitwise operations and assign the result to the same variable. The bitwise right shift assignment operator (>>=) shifts the bits of a variable to the right by a specified number of positions and stores the result in the same variable. The bitwise left shift assignment operator (<<=) shifts the bits of a variable to the left by a specified number of positions and stores the result in the same variable. These operators are useful in simplifying and shortening code that involves assigning and manipulating values in a single step.

Here are some Frequently Asked Questions on Assignment Operator in Python:

Q1 – Can I use the assignment operator to assign multiple values to multiple variables at once? Ans – Yes, you can use the assignment operator to assign multiple values to multiple variables at once, separated by commas. For example, "x, y, z = 1, 2, 3" would assign the value 1 to x, 2 to y, and 3 to z.

Q2 – Is it possible to chain assignment operators in Python? Ans – Yes, you can chain assignment operators in Python to perform multiple operations in one line of code. For example, "x = y = z = 1" would assign the value 1 to all three variables.

Q3 – How do I perform a conditional assignment in Python? Ans – To perform a conditional assignment in Python, you can use the ternary operator. For example, "x = a (if a > b) else b" would assign the value of a to x if a is greater than b, otherwise it would assign the value of b to x.

Q4 – What happens if I use an undefined variable in an assignment operation in Python? Ans – If you use an undefined variable in an assignment operation in Python, you will get a NameError. Make sure you have defined the variable before trying to assign a value to it.

Q5 – Can I use assignment operators with non-numeric data types in Python? Ans – Yes, you can use assignment operators with non-numeric data types in Python, such as strings or lists. For example, "my_list += [4, 5, 6]" would append the values 4, 5, and 6 to the end of the list named my_list.

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Save my name, email, and website in this browser for the next time I comment.

  • Linked List
  • Segment Tree
  • Backtracking
  • Dynamic Programming
  • Greedy Algorithm
  • Operating System
  • Company Placement
  • Interview Tips
  • General Interview Questions
  • Data Structure
  • Other Topics
  • Computational Geometry
  • Game Theory

Related Post

Python list functions & python list methods, python interview questions, namespaces and scope in python, what is the difference between append and extend in python, python program to check for the perfect square, python program to find the sum of first n natural numbers.

Python Enhancement Proposals

  • Python »
  • PEP Index »

PEP 572 – Assignment Expressions

The importance of real code, exceptional cases, scope of the target, relative precedence of :=, change to evaluation order, differences between assignment expressions and assignment statements, specification changes during implementation, _pydecimal.py, datetime.py, sysconfig.py, simplifying list comprehensions, capturing condition values, changing the scope rules for comprehensions, alternative spellings, special-casing conditional statements, special-casing comprehensions, lowering operator precedence, allowing commas to the right, always requiring parentheses, why not just turn existing assignment into an expression, with assignment expressions, why bother with assignment statements, why not use a sublocal scope and prevent namespace pollution, style guide recommendations, acknowledgements, a numeric example, appendix b: rough code translations for comprehensions, appendix c: no changes to scope semantics.

This is a proposal for creating a way to assign to variables within an expression using the notation NAME := expr .

As part of this change, there is also an update to dictionary comprehension evaluation order to ensure key expressions are executed before value expressions (allowing the key to be bound to a name and then re-used as part of calculating the corresponding value).

During discussion of this PEP, the operator became informally known as “the walrus operator”. The construct’s formal name is “Assignment Expressions” (as per the PEP title), but they may also be referred to as “Named Expressions” (e.g. the CPython reference implementation uses that name internally).

Naming the result of an expression is an important part of programming, allowing a descriptive name to be used in place of a longer expression, and permitting reuse. Currently, this feature is available only in statement form, making it unavailable in list comprehensions and other expression contexts.

Additionally, naming sub-parts of a large expression can assist an interactive debugger, providing useful display hooks and partial results. Without a way to capture sub-expressions inline, this would require refactoring of the original code; with assignment expressions, this merely requires the insertion of a few name := markers. Removing the need to refactor reduces the likelihood that the code be inadvertently changed as part of debugging (a common cause of Heisenbugs), and is easier to dictate to another programmer.

During the development of this PEP many people (supporters and critics both) have had a tendency to focus on toy examples on the one hand, and on overly complex examples on the other.

The danger of toy examples is twofold: they are often too abstract to make anyone go “ooh, that’s compelling”, and they are easily refuted with “I would never write it that way anyway”.

The danger of overly complex examples is that they provide a convenient strawman for critics of the proposal to shoot down (“that’s obfuscated”).

Yet there is some use for both extremely simple and extremely complex examples: they are helpful to clarify the intended semantics. Therefore, there will be some of each below.

However, in order to be compelling , examples should be rooted in real code, i.e. code that was written without any thought of this PEP, as part of a useful application, however large or small. Tim Peters has been extremely helpful by going over his own personal code repository and picking examples of code he had written that (in his view) would have been clearer if rewritten with (sparing) use of assignment expressions. His conclusion: the current proposal would have allowed a modest but clear improvement in quite a few bits of code.

Another use of real code is to observe indirectly how much value programmers place on compactness. Guido van Rossum searched through a Dropbox code base and discovered some evidence that programmers value writing fewer lines over shorter lines.

Case in point: Guido found several examples where a programmer repeated a subexpression, slowing down the program, in order to save one line of code, e.g. instead of writing:

they would write:

Another example illustrates that programmers sometimes do more work to save an extra level of indentation:

This code tries to match pattern2 even if pattern1 has a match (in which case the match on pattern2 is never used). The more efficient rewrite would have been:

Syntax and semantics

In most contexts where arbitrary Python expressions can be used, a named expression can appear. This is of the form NAME := expr where expr is any valid Python expression other than an unparenthesized tuple, and NAME is an identifier.

The value of such a named expression is the same as the incorporated expression, with the additional side-effect that the target is assigned that value:

There are a few places where assignment expressions are not allowed, in order to avoid ambiguities or user confusion:

This rule is included to simplify the choice for the user between an assignment statement and an assignment expression – there is no syntactic position where both are valid.

Again, this rule is included to avoid two visually similar ways of saying the same thing.

This rule is included to disallow excessively confusing code, and because parsing keyword arguments is complex enough already.

This rule is included to discourage side effects in a position whose exact semantics are already confusing to many users (cf. the common style recommendation against mutable default values), and also to echo the similar prohibition in calls (the previous bullet).

The reasoning here is similar to the two previous cases; this ungrouped assortment of symbols and operators composed of : and = is hard to read correctly.

This allows lambda to always bind less tightly than := ; having a name binding at the top level inside a lambda function is unlikely to be of value, as there is no way to make use of it. In cases where the name will be used more than once, the expression is likely to need parenthesizing anyway, so this prohibition will rarely affect code.

This shows that what looks like an assignment operator in an f-string is not always an assignment operator. The f-string parser uses : to indicate formatting options. To preserve backwards compatibility, assignment operator usage inside of f-strings must be parenthesized. As noted above, this usage of the assignment operator is not recommended.

An assignment expression does not introduce a new scope. In most cases the scope in which the target will be bound is self-explanatory: it is the current scope. If this scope contains a nonlocal or global declaration for the target, the assignment expression honors that. A lambda (being an explicit, if anonymous, function definition) counts as a scope for this purpose.

There is one special case: an assignment expression occurring in a list, set or dict comprehension or in a generator expression (below collectively referred to as “comprehensions”) binds the target in the containing scope, honoring a nonlocal or global declaration for the target in that scope, if one exists. For the purpose of this rule the containing scope of a nested comprehension is the scope that contains the outermost comprehension. A lambda counts as a containing scope.

The motivation for this special case is twofold. First, it allows us to conveniently capture a “witness” for an any() expression, or a counterexample for all() , for example:

Second, it allows a compact way of updating mutable state from a comprehension, for example:

However, an assignment expression target name cannot be the same as a for -target name appearing in any comprehension containing the assignment expression. The latter names are local to the comprehension in which they appear, so it would be contradictory for a contained use of the same name to refer to the scope containing the outermost comprehension instead.

For example, [i := i+1 for i in range(5)] is invalid: the for i part establishes that i is local to the comprehension, but the i := part insists that i is not local to the comprehension. The same reason makes these examples invalid too:

While it’s technically possible to assign consistent semantics to these cases, it’s difficult to determine whether those semantics actually make sense in the absence of real use cases. Accordingly, the reference implementation [1] will ensure that such cases raise SyntaxError , rather than executing with implementation defined behaviour.

This restriction applies even if the assignment expression is never executed:

For the comprehension body (the part before the first “for” keyword) and the filter expression (the part after “if” and before any nested “for”), this restriction applies solely to target names that are also used as iteration variables in the comprehension. Lambda expressions appearing in these positions introduce a new explicit function scope, and hence may use assignment expressions with no additional restrictions.

Due to design constraints in the reference implementation (the symbol table analyser cannot easily detect when names are re-used between the leftmost comprehension iterable expression and the rest of the comprehension), named expressions are disallowed entirely as part of comprehension iterable expressions (the part after each “in”, and before any subsequent “if” or “for” keyword):

A further exception applies when an assignment expression occurs in a comprehension whose containing scope is a class scope. If the rules above were to result in the target being assigned in that class’s scope, the assignment expression is expressly invalid. This case also raises SyntaxError :

(The reason for the latter exception is the implicit function scope created for comprehensions – there is currently no runtime mechanism for a function to refer to a variable in the containing class scope, and we do not want to add such a mechanism. If this issue ever gets resolved this special case may be removed from the specification of assignment expressions. Note that the problem already exists for using a variable defined in the class scope from a comprehension.)

See Appendix B for some examples of how the rules for targets in comprehensions translate to equivalent code.

The := operator groups more tightly than a comma in all syntactic positions where it is legal, but less tightly than all other operators, including or , and , not , and conditional expressions ( A if C else B ). As follows from section “Exceptional cases” above, it is never allowed at the same level as = . In case a different grouping is desired, parentheses should be used.

The := operator may be used directly in a positional function call argument; however it is invalid directly in a keyword argument.

Some examples to clarify what’s technically valid or invalid:

Most of the “valid” examples above are not recommended, since human readers of Python source code who are quickly glancing at some code may miss the distinction. But simple cases are not objectionable:

This PEP recommends always putting spaces around := , similar to PEP 8 ’s recommendation for = when used for assignment, whereas the latter disallows spaces around = used for keyword arguments.)

In order to have precisely defined semantics, the proposal requires evaluation order to be well-defined. This is technically not a new requirement, as function calls may already have side effects. Python already has a rule that subexpressions are generally evaluated from left to right. However, assignment expressions make these side effects more visible, and we propose a single change to the current evaluation order:

  • In a dict comprehension {X: Y for ...} , Y is currently evaluated before X . We propose to change this so that X is evaluated before Y . (In a dict display like {X: Y} this is already the case, and also in dict((X, Y) for ...) which should clearly be equivalent to the dict comprehension.)

Most importantly, since := is an expression, it can be used in contexts where statements are illegal, including lambda functions and comprehensions.

Conversely, assignment expressions don’t support the advanced features found in assignment statements:

  • Multiple targets are not directly supported: x = y = z = 0 # Equivalent: (z := (y := (x := 0)))
  • Single assignment targets other than a single NAME are not supported: # No equivalent a [ i ] = x self . rest = []
  • Priority around commas is different: x = 1 , 2 # Sets x to (1, 2) ( x := 1 , 2 ) # Sets x to 1
  • Iterable packing and unpacking (both regular or extended forms) are not supported: # Equivalent needs extra parentheses loc = x , y # Use (loc := (x, y)) info = name , phone , * rest # Use (info := (name, phone, *rest)) # No equivalent px , py , pz = position name , phone , email , * other_info = contact
  • Inline type annotations are not supported: # Closest equivalent is "p: Optional[int]" as a separate declaration p : Optional [ int ] = None
  • Augmented assignment is not supported: total += tax # Equivalent: (total := total + tax)

The following changes have been made based on implementation experience and additional review after the PEP was first accepted and before Python 3.8 was released:

  • for consistency with other similar exceptions, and to avoid locking in an exception name that is not necessarily going to improve clarity for end users, the originally proposed TargetScopeError subclass of SyntaxError was dropped in favour of just raising SyntaxError directly. [3]
  • due to a limitation in CPython’s symbol table analysis process, the reference implementation raises SyntaxError for all uses of named expressions inside comprehension iterable expressions, rather than only raising them when the named expression target conflicts with one of the iteration variables in the comprehension. This could be revisited given sufficiently compelling examples, but the extra complexity needed to implement the more selective restriction doesn’t seem worthwhile for purely hypothetical use cases.

Examples from the Python standard library

env_base is only used on these lines, putting its assignment on the if moves it as the “header” of the block.

  • Current: env_base = os . environ . get ( "PYTHONUSERBASE" , None ) if env_base : return env_base
  • Improved: if env_base := os . environ . get ( "PYTHONUSERBASE" , None ): return env_base

Avoid nested if and remove one indentation level.

  • Current: if self . _is_special : ans = self . _check_nans ( context = context ) if ans : return ans
  • Improved: if self . _is_special and ( ans := self . _check_nans ( context = context )): return ans

Code looks more regular and avoid multiple nested if. (See Appendix A for the origin of this example.)

  • Current: reductor = dispatch_table . get ( cls ) if reductor : rv = reductor ( x ) else : reductor = getattr ( x , "__reduce_ex__" , None ) if reductor : rv = reductor ( 4 ) else : reductor = getattr ( x , "__reduce__" , None ) if reductor : rv = reductor () else : raise Error ( "un(deep)copyable object of type %s " % cls )
  • Improved: if reductor := dispatch_table . get ( cls ): rv = reductor ( x ) elif reductor := getattr ( x , "__reduce_ex__" , None ): rv = reductor ( 4 ) elif reductor := getattr ( x , "__reduce__" , None ): rv = reductor () else : raise Error ( "un(deep)copyable object of type %s " % cls )

tz is only used for s += tz , moving its assignment inside the if helps to show its scope.

  • Current: s = _format_time ( self . _hour , self . _minute , self . _second , self . _microsecond , timespec ) tz = self . _tzstr () if tz : s += tz return s
  • Improved: s = _format_time ( self . _hour , self . _minute , self . _second , self . _microsecond , timespec ) if tz := self . _tzstr (): s += tz return s

Calling fp.readline() in the while condition and calling .match() on the if lines make the code more compact without making it harder to understand.

  • Current: while True : line = fp . readline () if not line : break m = define_rx . match ( line ) if m : n , v = m . group ( 1 , 2 ) try : v = int ( v ) except ValueError : pass vars [ n ] = v else : m = undef_rx . match ( line ) if m : vars [ m . group ( 1 )] = 0
  • Improved: while line := fp . readline (): if m := define_rx . match ( line ): n , v = m . group ( 1 , 2 ) try : v = int ( v ) except ValueError : pass vars [ n ] = v elif m := undef_rx . match ( line ): vars [ m . group ( 1 )] = 0

A list comprehension can map and filter efficiently by capturing the condition:

Similarly, a subexpression can be reused within the main expression, by giving it a name on first use:

Note that in both cases the variable y is bound in the containing scope (i.e. at the same level as results or stuff ).

Assignment expressions can be used to good effect in the header of an if or while statement:

Particularly with the while loop, this can remove the need to have an infinite loop, an assignment, and a condition. It also creates a smooth parallel between a loop which simply uses a function call as its condition, and one which uses that as its condition but also uses the actual value.

An example from the low-level UNIX world:

Rejected alternative proposals

Proposals broadly similar to this one have come up frequently on python-ideas. Below are a number of alternative syntaxes, some of them specific to comprehensions, which have been rejected in favour of the one given above.

A previous version of this PEP proposed subtle changes to the scope rules for comprehensions, to make them more usable in class scope and to unify the scope of the “outermost iterable” and the rest of the comprehension. However, this part of the proposal would have caused backwards incompatibilities, and has been withdrawn so the PEP can focus on assignment expressions.

Broadly the same semantics as the current proposal, but spelled differently.

Since EXPR as NAME already has meaning in import , except and with statements (with different semantics), this would create unnecessary confusion or require special-casing (e.g. to forbid assignment within the headers of these statements).

(Note that with EXPR as VAR does not simply assign the value of EXPR to VAR – it calls EXPR.__enter__() and assigns the result of that to VAR .)

Additional reasons to prefer := over this spelling include:

  • In if f(x) as y the assignment target doesn’t jump out at you – it just reads like if f x blah blah and it is too similar visually to if f(x) and y .
  • import foo as bar
  • except Exc as var
  • with ctxmgr() as var

To the contrary, the assignment expression does not belong to the if or while that starts the line, and we intentionally allow assignment expressions in other contexts as well.

  • NAME = EXPR
  • if NAME := EXPR

reinforces the visual recognition of assignment expressions.

This syntax is inspired by languages such as R and Haskell, and some programmable calculators. (Note that a left-facing arrow y <- f(x) is not possible in Python, as it would be interpreted as less-than and unary minus.) This syntax has a slight advantage over ‘as’ in that it does not conflict with with , except and import , but otherwise is equivalent. But it is entirely unrelated to Python’s other use of -> (function return type annotations), and compared to := (which dates back to Algol-58) it has a much weaker tradition.

This has the advantage that leaked usage can be readily detected, removing some forms of syntactic ambiguity. However, this would be the only place in Python where a variable’s scope is encoded into its name, making refactoring harder.

Execution order is inverted (the indented body is performed first, followed by the “header”). This requires a new keyword, unless an existing keyword is repurposed (most likely with: ). See PEP 3150 for prior discussion on this subject (with the proposed keyword being given: ).

This syntax has fewer conflicts than as does (conflicting only with the raise Exc from Exc notation), but is otherwise comparable to it. Instead of paralleling with expr as target: (which can be useful but can also be confusing), this has no parallels, but is evocative.

One of the most popular use-cases is if and while statements. Instead of a more general solution, this proposal enhances the syntax of these two statements to add a means of capturing the compared value:

This works beautifully if and ONLY if the desired condition is based on the truthiness of the captured value. It is thus effective for specific use-cases (regex matches, socket reads that return '' when done), and completely useless in more complicated cases (e.g. where the condition is f(x) < 0 and you want to capture the value of f(x) ). It also has no benefit to list comprehensions.

Advantages: No syntactic ambiguities. Disadvantages: Answers only a fraction of possible use-cases, even in if / while statements.

Another common use-case is comprehensions (list/set/dict, and genexps). As above, proposals have been made for comprehension-specific solutions.

This brings the subexpression to a location in between the ‘for’ loop and the expression. It introduces an additional language keyword, which creates conflicts. Of the three, where reads the most cleanly, but also has the greatest potential for conflict (e.g. SQLAlchemy and numpy have where methods, as does tkinter.dnd.Icon in the standard library).

As above, but reusing the with keyword. Doesn’t read too badly, and needs no additional language keyword. Is restricted to comprehensions, though, and cannot as easily be transformed into “longhand” for-loop syntax. Has the C problem that an equals sign in an expression can now create a name binding, rather than performing a comparison. Would raise the question of why “with NAME = EXPR:” cannot be used as a statement on its own.

As per option 2, but using as rather than an equals sign. Aligns syntactically with other uses of as for name binding, but a simple transformation to for-loop longhand would create drastically different semantics; the meaning of with inside a comprehension would be completely different from the meaning as a stand-alone statement, while retaining identical syntax.

Regardless of the spelling chosen, this introduces a stark difference between comprehensions and the equivalent unrolled long-hand form of the loop. It is no longer possible to unwrap the loop into statement form without reworking any name bindings. The only keyword that can be repurposed to this task is with , thus giving it sneakily different semantics in a comprehension than in a statement; alternatively, a new keyword is needed, with all the costs therein.

There are two logical precedences for the := operator. Either it should bind as loosely as possible, as does statement-assignment; or it should bind more tightly than comparison operators. Placing its precedence between the comparison and arithmetic operators (to be precise: just lower than bitwise OR) allows most uses inside while and if conditions to be spelled without parentheses, as it is most likely that you wish to capture the value of something, then perform a comparison on it:

Once find() returns -1, the loop terminates. If := binds as loosely as = does, this would capture the result of the comparison (generally either True or False ), which is less useful.

While this behaviour would be convenient in many situations, it is also harder to explain than “the := operator behaves just like the assignment statement”, and as such, the precedence for := has been made as close as possible to that of = (with the exception that it binds tighter than comma).

Some critics have claimed that the assignment expressions should allow unparenthesized tuples on the right, so that these two would be equivalent:

(With the current version of the proposal, the latter would be equivalent to ((point := x), y) .)

However, adopting this stance would logically lead to the conclusion that when used in a function call, assignment expressions also bind less tight than comma, so we’d have the following confusing equivalence:

The less confusing option is to make := bind more tightly than comma.

It’s been proposed to just always require parentheses around an assignment expression. This would resolve many ambiguities, and indeed parentheses will frequently be needed to extract the desired subexpression. But in the following cases the extra parentheses feel redundant:

Frequently Raised Objections

C and its derivatives define the = operator as an expression, rather than a statement as is Python’s way. This allows assignments in more contexts, including contexts where comparisons are more common. The syntactic similarity between if (x == y) and if (x = y) belies their drastically different semantics. Thus this proposal uses := to clarify the distinction.

The two forms have different flexibilities. The := operator can be used inside a larger expression; the = statement can be augmented to += and its friends, can be chained, and can assign to attributes and subscripts.

Previous revisions of this proposal involved sublocal scope (restricted to a single statement), preventing name leakage and namespace pollution. While a definite advantage in a number of situations, this increases complexity in many others, and the costs are not justified by the benefits. In the interests of language simplicity, the name bindings created here are exactly equivalent to any other name bindings, including that usage at class or module scope will create externally-visible names. This is no different from for loops or other constructs, and can be solved the same way: del the name once it is no longer needed, or prefix it with an underscore.

(The author wishes to thank Guido van Rossum and Christoph Groth for their suggestions to move the proposal in this direction. [2] )

As expression assignments can sometimes be used equivalently to statement assignments, the question of which should be preferred will arise. For the benefit of style guides such as PEP 8 , two recommendations are suggested.

  • If either assignment statements or assignment expressions can be used, prefer statements; they are a clear declaration of intent.
  • If using assignment expressions would lead to ambiguity about execution order, restructure it to use statements instead.

The authors wish to thank Alyssa Coghlan and Steven D’Aprano for their considerable contributions to this proposal, and members of the core-mentorship mailing list for assistance with implementation.

Appendix A: Tim Peters’s findings

Here’s a brief essay Tim Peters wrote on the topic.

I dislike “busy” lines of code, and also dislike putting conceptually unrelated logic on a single line. So, for example, instead of:

instead. So I suspected I’d find few places I’d want to use assignment expressions. I didn’t even consider them for lines already stretching halfway across the screen. In other cases, “unrelated” ruled:

is a vast improvement over the briefer:

The original two statements are doing entirely different conceptual things, and slamming them together is conceptually insane.

In other cases, combining related logic made it harder to understand, such as rewriting:

as the briefer:

The while test there is too subtle, crucially relying on strict left-to-right evaluation in a non-short-circuiting or method-chaining context. My brain isn’t wired that way.

But cases like that were rare. Name binding is very frequent, and “sparse is better than dense” does not mean “almost empty is better than sparse”. For example, I have many functions that return None or 0 to communicate “I have nothing useful to return in this case, but since that’s expected often I’m not going to annoy you with an exception”. This is essentially the same as regular expression search functions returning None when there is no match. So there was lots of code of the form:

I find that clearer, and certainly a bit less typing and pattern-matching reading, as:

It’s also nice to trade away a small amount of horizontal whitespace to get another _line_ of surrounding code on screen. I didn’t give much weight to this at first, but it was so very frequent it added up, and I soon enough became annoyed that I couldn’t actually run the briefer code. That surprised me!

There are other cases where assignment expressions really shine. Rather than pick another from my code, Kirill Balunov gave a lovely example from the standard library’s copy() function in copy.py :

The ever-increasing indentation is semantically misleading: the logic is conceptually flat, “the first test that succeeds wins”:

Using easy assignment expressions allows the visual structure of the code to emphasize the conceptual flatness of the logic; ever-increasing indentation obscured it.

A smaller example from my code delighted me, both allowing to put inherently related logic in a single line, and allowing to remove an annoying “artificial” indentation level:

That if is about as long as I want my lines to get, but remains easy to follow.

So, in all, in most lines binding a name, I wouldn’t use assignment expressions, but because that construct is so very frequent, that leaves many places I would. In most of the latter, I found a small win that adds up due to how often it occurs, and in the rest I found a moderate to major win. I’d certainly use it more often than ternary if , but significantly less often than augmented assignment.

I have another example that quite impressed me at the time.

Where all variables are positive integers, and a is at least as large as the n’th root of x, this algorithm returns the floor of the n’th root of x (and roughly doubling the number of accurate bits per iteration):

It’s not obvious why that works, but is no more obvious in the “loop and a half” form. It’s hard to prove correctness without building on the right insight (the “arithmetic mean - geometric mean inequality”), and knowing some non-trivial things about how nested floor functions behave. That is, the challenges are in the math, not really in the coding.

If you do know all that, then the assignment-expression form is easily read as “while the current guess is too large, get a smaller guess”, where the “too large?” test and the new guess share an expensive sub-expression.

To my eyes, the original form is harder to understand:

This appendix attempts to clarify (though not specify) the rules when a target occurs in a comprehension or in a generator expression. For a number of illustrative examples we show the original code, containing a comprehension, and the translation, where the comprehension has been replaced by an equivalent generator function plus some scaffolding.

Since [x for ...] is equivalent to list(x for ...) these examples all use list comprehensions without loss of generality. And since these examples are meant to clarify edge cases of the rules, they aren’t trying to look like real code.

Note: comprehensions are already implemented via synthesizing nested generator functions like those in this appendix. The new part is adding appropriate declarations to establish the intended scope of assignment expression targets (the same scope they resolve to as if the assignment were performed in the block containing the outermost comprehension). For type inference purposes, these illustrative expansions do not imply that assignment expression targets are always Optional (but they do indicate the target binding scope).

Let’s start with a reminder of what code is generated for a generator expression without assignment expression.

  • Original code (EXPR usually references VAR): def f (): a = [ EXPR for VAR in ITERABLE ]
  • Translation (let’s not worry about name conflicts): def f (): def genexpr ( iterator ): for VAR in iterator : yield EXPR a = list ( genexpr ( iter ( ITERABLE )))

Let’s add a simple assignment expression.

  • Original code: def f (): a = [ TARGET := EXPR for VAR in ITERABLE ]
  • Translation: def f (): if False : TARGET = None # Dead code to ensure TARGET is a local variable def genexpr ( iterator ): nonlocal TARGET for VAR in iterator : TARGET = EXPR yield TARGET a = list ( genexpr ( iter ( ITERABLE )))

Let’s add a global TARGET declaration in f() .

  • Original code: def f (): global TARGET a = [ TARGET := EXPR for VAR in ITERABLE ]
  • Translation: def f (): global TARGET def genexpr ( iterator ): global TARGET for VAR in iterator : TARGET = EXPR yield TARGET a = list ( genexpr ( iter ( ITERABLE )))

Or instead let’s add a nonlocal TARGET declaration in f() .

  • Original code: def g (): TARGET = ... def f (): nonlocal TARGET a = [ TARGET := EXPR for VAR in ITERABLE ]
  • Translation: def g (): TARGET = ... def f (): nonlocal TARGET def genexpr ( iterator ): nonlocal TARGET for VAR in iterator : TARGET = EXPR yield TARGET a = list ( genexpr ( iter ( ITERABLE )))

Finally, let’s nest two comprehensions.

  • Original code: def f (): a = [[ TARGET := i for i in range ( 3 )] for j in range ( 2 )] # I.e., a = [[0, 1, 2], [0, 1, 2]] print ( TARGET ) # prints 2
  • Translation: def f (): if False : TARGET = None def outer_genexpr ( outer_iterator ): nonlocal TARGET def inner_generator ( inner_iterator ): nonlocal TARGET for i in inner_iterator : TARGET = i yield i for j in outer_iterator : yield list ( inner_generator ( range ( 3 ))) a = list ( outer_genexpr ( range ( 2 ))) print ( TARGET )

Because it has been a point of confusion, note that nothing about Python’s scoping semantics is changed. Function-local scopes continue to be resolved at compile time, and to have indefinite temporal extent at run time (“full closures”). Example:

This document has been placed in the public domain.

Source: https://github.com/python/peps/blob/main/peps/pep-0572.rst

Last modified: 2023-10-11 12:05:51 GMT

IMAGES

  1. Python Operator

    all assignment operators in python program

  2. 7 Types of Python Operators that will ease your programming

    all assignment operators in python program

  3. 7 Types of Python Operators that will ease your programming

    all assignment operators in python program

  4. PPT

    all assignment operators in python program

  5. Python Operators

    all assignment operators in python program

  6. Python Tutorials: Assignment Operators In python

    all assignment operators in python program

VIDEO

  1. Assignment

  2. L-5.4 Assignment Operators

  3. PYTHON OPERATORS ASSIGNMENT OPREATORS

  4. Python Programming 4

  5. # python assignment operators # python #hindi #datascience

  6. Grand Assignment

COMMENTS

  1. Assignment Operators in Python

    Assignment Operator. Assignment Operators are used to assign values to variables. This operator is used to assign the value of the right side of the expression to the left side operand. Python. # Assigning values using # Assignment Operator a = 3 b = 5 c = a + b # Output print(c) Output. 8.

  2. Python Assignment Operators

    W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more.

  3. Python's Assignment Operator: Write Robust Assignments

    To create a new variable or to update the value of an existing one in Python, you'll use an assignment statement. This statement has the following three components: A left operand, which must be a variable. The assignment operator ( =) A right operand, which can be a concrete value, an object, or an expression.

  4. Python

    Python Assignment Operator. The = (equal to) symbol is defined as assignment operator in Python. The value of Python expression on its right is assigned to a single variable on its left. The = symbol as in programming in general (and Python in particular) should not be confused with its usage in Mathematics, where it states that the expressions ...

  5. Python Operators (With Examples)

    Assignment operators are used to assign values to variables. For example, # assign 5 to x x = 5. Here, = is an assignment operator that assigns 5 to x. Here's a list of different assignment operators available in Python.

  6. Python Assignment Operators

    Assignment operators in Python. The above code is useful when we want to update the same number. We can also use two different numbers and use the assignment operators to apply them on two different values. num_one = 6. num_two = 3. print(num_one) num_one += num_two. print(num_one) num_one -= num_two.

  7. Python Assignment Operators

    In Python, an assignment operator is used to assign a value to a variable. The assignment operator is a single equals sign (=). Here is an example of using the assignment operator to assign a value to a variable: x = 5. In this example, the variable x is assigned the value 5. There are also several compound assignment operators in Python, which ...

  8. Python Assignment Operators

    Operator Multiplication (*=) Operator Division (/=) Operator Modulus (%=) Operator Exponentiation (**=) Operator Floor Division (//=) Conclusion. Python assignment operators are one of the operator types and assign values to variables. We use arithmetic operators here in combination with a variable. Let's take a look at some examples.

  9. Python Assignment Operators

    In this example program, We declared 2 integer values, a Total, and we assigned values 7 and 21, respectively. The print statements will display the output of the Total after using the Python Assignment Operators on a and Total. Let us see the functionalities of all of them. First functionality,

  10. Assignment Operators

    This is a category of operators which is used to assign values to a variable. The = operator is an assignment operator, but not the only one. Here's a list of all the assignment operators supported in Python: Operator. Purpose. Notation. =. Assign. In-fix.

  11. Operators and Expressions in Python

    In programming, an operator is usually a symbol or combination of symbols that allows you to perform a ... check out The Walrus Operator: Python 3.8 Assignment Expressions. Unlike regular assignments, assignment expressions do have a return value, which is why they ... All operators that Python supports have a precedence compared to other ...

  12. Different Assignment operators in Python

    The Simple assignment operator in Python is denoted by = and is used to assign values from the right side of the operator to the value on the left side. Input: a = b + c. Add and equal operator. This operator adds the value on the right side to the value on the left side and stores the result in the operand on the left side. Input: a = 5. a += 10.

  13. Python Operators: Arithmetic, Assignment, Comparison, Logical, Identity

    Arithmetic operators perform the common mathematical operation on the numeric operands. The arithmetic operators return the type of result depends on the type of operands, as below. If both operands are integers, then the result is an integer and no conversion is needed. The following table lists all the arithmetic operators in Python:

  14. Assignment Operators in Python

    The primary assignment operator is the simple assignment operator ("="). We then learned that Python supports more complex assignment operators that can be used to calculate values in place. The assignment operators can be used to calculate mathematical, logical, and bitwise operations.

  15. Python Assignment Operator

    Python comes with a couple of shorthand assignment operators. Some of the most common ones include the following: Operator. Meaning. +=. Add the value on the right to the variable on the left. -=. Subtract the value on the right from the variable on the left. *=.

  16. How to Use Assignment Operators in Python

    So if you memorize the list of all the python operators then you're going to be able to use each one of these assignment operators quite easily. The very first thing I'm going to do is let's first make sure that we can print out the total. So right here we have a total and it's an integer that equals 100. ... So in review, that is how you can ...

  17. Assignment Operator in Python

    The simple assignment operator is the most commonly used operator in Python. It is used to assign a value to a variable. The syntax for the simple assignment operator is: variable = value. Here, the value on the right-hand side of the equals sign is assigned to the variable on the left-hand side. For example.

  18. Python Operators

    The Python programming language provides arithmetic operators that perform addition, subtraction, multiplication, and division. It works the same as basic mathematics. ... Also, there are shorthand assignment operators in Python. For example, a+=2 which is equivalent to a = a+2. Operator Meaning Equivalent = (Assign) a=5Assign 5 to variable a ...

  19. Python Operators

    But to simplify code, and reduce redundancy, Python also includes arithmetic assignment operators. This includes the += operator in Python used for addition assignment, //= floor division assignment operator, and others. Here's a list of all the arithmetic assignment operators in Python. Operator. Description. +=. a+=b is equivalent to a=a+b ...

  20. PEP 572

    Unparenthesized assignment expressions are prohibited for the value of a keyword argument in a call. Example: foo(x = y := f(x)) # INVALID foo(x=(y := f(x))) # Valid, though probably confusing. This rule is included to disallow excessively confusing code, and because parsing keyword arguments is complex enough already.

  21. Python Operators from Scratch!!!

    Below is the simple python snippet that you can use as a reference: # Assigning values to variables. a = 10. b = 11 # Identity is operator. print('a is b is',a is b) # Identity is not operator. print('a is not b is',a is not b) When you run the above python script you will be prompted by the following output.