A Simple Introduction to List Comprehension in Python

List comprehension is a compact way of creating lists. The simple formula is [ expression + context ].

- Expression: What to do with each list element?
- Context: What list elements to select? It consists of an arbitrary number of for and if statements.

The example [x for x in range(3)] creates the list [0, 1, 2].

In this article, you will learn everything you need to know about list comprehension in Python. Being hated by newbies, experienced Python coders can’t live without this awesome Python feature.

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[barriesimpson]

Excellent! Thank you, I have spent 3 days looking for a simple, understandable explanation and this is it.

[evelynnmimijae]

Here's my code:

import time as t

def f1(n):
return ''.join([str(x) for x in range(n)])

def f2(n):
s = ''
for x in range(n):
s += str(x)
return s

n = 10**6
t1 = t.time()
f1(n)
t2 = t.time()
f2(n)
t3 = t.time()

print(t3 - t2 > t2 - t1)

The solution is True, but I got False. I researched and found that there are various reasons for this. However, I am not sure where to start on finding out exactly why and if this will affect future String puzzles.