Python List Comprehension

List comprehension is a really weird thing when I first saw it, but after a while it get’s trivial. Today, we will be exploring this syntax.

Basic for-loop:

lst = []
for i in arr:
    lst.append(i)

list comprehension:

a = [i for i in arr]

essentially, the syntax for list comprehension is “expression” for “item” in “list”. And the output will be a list as well.

Another non-trivial code comparison.

basic for-loop

list comprehension

So why use list comprehension?

Apart from shorter code, it is supposedly a tad faster than the traditional loop. However actual performance depends on your logic expression. In the end, I still prefer the basic for-loop because it is much more readable for someone coming from another language.