What are lambda functions?

A lambda function is a small, anonymous function that can be defined in a single line of code. In Python, "anonymous" means the function is created without a name (unlike a standard function defined with the def keyword).

Here are the key characteristics of lambda functions:

1. Simple Syntax

The basic structure is:
lambda arguments : expression

• Keyword: lambda
• Arguments: Just like regular functions, they can have one or many (separated by commas).
• Expression: A single piece of code that is executed and automatically returned. You don’t need to write the return keyword.

2. Comparison with def

A lambda is essentially a shortcut for a simple function.

Standard way:

def square(x):
    return x * x

Lambda way:

square = lambda x: x * x

3. Why use them?

Lambdas are best used for temporary tasks where you don't want to go through the effort of writing a full function definition. Common uses include:

• Passing functions as arguments: Many Python functions (like sorted(), map(), or filter()) expect another function as an input. Lambdas are perfect for this.
• Closures: As seen in your experiment, they can "capture" variables from a parent function (like n in make_adder).
• Readability: For very simple logic, keeping the code on one line can sometimes make the main logic easier to follow.

4. Limitations

• They can only contain one single expression. You cannot use loops, multiple lines of logic, or if/else blocks (unless you use a ternary operator).
• They are harder to debug because they don't have a name in error messages (it will just say <lambda>).

Labby's Tip: If your logic is complex or spans multiple lines, always use def. Use lambda only for simple, one-off transformations!