Python Functions and Lambda

1. Introduction

Functions are a fundamental part of programming in Python, allowing you to encapsulate code for reuse. Lambda functions offer a way to create small anonymous functions for short-term use.

2. Function Definition

A function is defined using the def keyword followed by the function name and parentheses. You can optionally include parameters.

Note: Functions help in organizing code, improving readability, and reducing redundancy.

3. Function Syntax

def function_name(parameters):
    # function body
    return value

Here's an example of a simple function:

def add(a, b):
    return a + b

result = add(5, 3)
print(result)  # Output: 8

4. Lambda Functions

Lambda functions are defined using the lambda keyword. They can take any number of arguments but can only have one expression.

lambda arguments: expression

Example of a lambda function:

multiply = lambda x, y: x * y
result = multiply(4, 5)
print(result)  # Output: 20

5. Best Practices

Key Takeaways:

Use functions to break down complex problems into manageable pieces.
Choose meaningful names for your functions to make them self-documenting.
Limit the use of lambda functions for simple operations.

6. FAQ

What is the difference between a function and a lambda?

A function is defined using def and can have multiple expressions, while a lambda is defined using lambda and can only have one expression.

Can lambda functions take multiple arguments?

Yes, lambda functions can take multiple arguments, but they can only contain a single expression.

When should I use lambda functions?

Use lambda functions for simple operations that can be defined in a single line, particularly when passing them as arguments to higher-order functions such as map, filter, or sorted.