lambdas

Lambdas can often achieve the same work as a function, more concisely. Concise expressive code is good, because it enables you to do more, quicker.

Let's say we want to sort a list, but use the square of each entry to evaluate their position, rather than the value itself:

1A = [1, -4, 7, 5, 4, -3, 2]
2print(sorted(A, key=lambda x: x * x)

This is equivalent to:

1def pow2(x):
2    return x * x
3
4A = [1, -4, 7, 5, 4, -3, 2]
5print(sorted(A, key=pow2))

So the key differences are:

• lambdas are anonymous functions
• lambdas don't have a return statement
• lambdas are one liners

There are, in fact, more differences, but none we want to focus on right now.