What is Lamda in Python; what are higher order functions.

 

Lambda in Python

In Python, lambda is an anonymous function (a function without a name). It is used for small, one-line functions where defining a full function using def would be unnecessary.

Syntax:

lambda arguments: expression

Example:

square = lambda x: x ** 2
print(square(5))  # Output: 25

Lambda functions are commonly used with higher-order functions like map(), filter(), and reduce().

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Higher-Order Functions

A higher-order function is a function that either:

1. Takes another function as an argument
2. Returns a function as output

Examples of Higher-Order Functions:

1. Using map() with lambda

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

2. Using filter() with lambda

numbers = [1, 2, 3, 4, 5]
evens = list(filter(lambda x: x % 2 == 0, numbers))
print(evens)  # Output: [2, 4]

3. Using reduce() with lambda (from functools module)

from functools import reduce
numbers = [1, 2, 3, 4]
product = reduce(lambda x, y: x * y, numbers)
print(product)  # Output: 24

Higher-order functions make Python code more concise, readable, and functional-programming-friendly. 🚀