Python lambda function is a small anonymous function that can have any number of arguments but can only have one expression. It is defined using the keyword lambda followed by the parameters and the expression. Lambda functions are often used for short and simple operations that do not require a separate function definition.

Lambda Function Syntax

lambda argument1,..,argumentN: expression

Simple lambda function

Here is an example of a simple lambda function that adds two numbers:

add = lambda x, y: x + y
print(add(2, 3)) # Output: 5

In this example, the lambda function add takes two arguments x and y, and returns their sum.

Python Lambda Function using map and filter

Lambda function in a filter()

Here is an example of using a lambda function with the filter() function to filter out even numbers from a list:

numbers = [1, 2, 3, 4, 5, 6, 7, 8, 9, 10]
even_numbers = list(filter(lambda x: x % 2 == 0, numbers))
print(even_numbers) # Output: [2, 4, 6, 8, 10]

Lambda function in a map()

Here is an example of using a lambda function with the map() function to square each element of a list:

numbers = [1, 2, 3, 4, 5]
squared_numbers = list(map(lambda x: x**2, numbers))
print(squared_numbers) # Output: [1, 4, 9, 16, 25]

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