Understanding Python Lambda Functions: A Comprehensive Guide | Python for Beginners

Table of Contents

1. Python Anonymous (Lambda) Functions
2. Examples
3. Tasks

1. Python Anonymous (Lambda) Functions

• A lambda function in Python is a small, anonymous function that can be defined without name.
• Lamdba functions are used to write functions consisting of a single statement.
• A lambda function can take any number of arguments, but can only have one expression.
• It is created using the 'lambda' keyword, and it is often used as an argument to a higher-order function (a function that takes another function as an argument).

Syntax:

The syntax of a lambda is

lambda arguments:express

2. Examples

Example #1: Add 10 Using Lambda in Python*

Following code is used to write the function to add 10 in given number.

def add_ten(x)
    return x + 10

above function can be written by the lamdba function in python.

 
add_ten = lambda x: x + 10
print(add_ten(5) # 15
 

Example #2: Multiply two numbers using lambda

use of lambda function to multiple two numbers

mul = lambda a, b : a * b
print(mul(2,4)) # 8

Example #3: Check Even Number

is_even = lambda x: x % 2 == 0
print(is_even(6))  # Output: True

Example #4: Immediately invoked function expression

(lambda x, y : x + y)(6,8) # 14

The lambda function above is defined and then immediately called with two arguments (6,8). it retuns the value 14, which is the sum of the arguments.

Example #5:

def multiply(x, y):
    return x * y
 
# Using lambda function to call multiply
result = (lambda x, y: multiply(x, y))(5, 3)
print(result)  # Output: 15
 
# Assigning lambda function to a variable
mult = lambda x, y: multiply(x, y)
result = mult(6, 2)
print(result)  # Output: 12

Example #6:

lambda x, y : x + y
 
_(6,8) # 14

Note: In the interactive interpreter, the single underscore**(_)** is bound to the last expression evalued.

Python Tutorial: How to Use of Lambda function

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{% include youtube-video.html video_type=video_type video_id=video_id %}

3. Tasks

Task 1: Add Two Numbers

Create a lambda function that adds two numbers.

Input: 3, 5
Expected Output: 8

Task 2: Multiply two number

Write a lambda function that multiplies two numbers.

Input: 4, 6

Expected Output: Output: 24

Python Tutorial: Multiplies two numbers

{% assign video_type = "short" %} {% assign video_id = "N3UAUI6cEVA" %}

{% include youtube-video.html video_type=video_type video_id=video_id %}

Task 3: Cube of a Number

Create a lambda function to compute the cube of a number.

Input: 3
Expected Output: 27

Task 4: Average of Two Numbers

Create a lambda function to compute the average of two numbers.

Input: 10, 20
Expected Output: 15.0