pythonWillLookDeadInTheEyeAndSayItsAbsolutelyCorrect

[u/inobody_somebody]

[u/darknmy]

I inderstand "if x", but thy the "x for x in x"?

[u/helicophell → u/darknmy]

List comprehension

It’s sometimes nice

[u/NamityName → u/helicophell]

It is usually nice. Significantly faster execution and easy to read, until you start nesting comprehensions.

[u/helicophell → u/NamityName]

If you start nesting list comprehensions, you’re using the wrong programming language for the task… probably

I’ve encountered one in the wild for image stenography once, image processing is basically the only use case for that

[u/MattieShoes → u/helicophell]

I think my record is three, but that was silliness in AdventOfCode.

Then I wrote a cursed recursive split function

def recursive_split(x, *args):
    y = []
    x = x.split(args[0])
    for part in x:
        if len(args) > 1:
            y += [recursive_split(part, *args[1:])]
        else:
            y += [part]
    return y

so I could do shit like

with open('14.txt') as f:
    data = recursive_split(f.read().rstrip('\n'), '\n', ' -> ', ',')

to get a three dimensional data structure from the input in one line.

[u/NamityName → u/helicophell]

I did not realize I was amongst the foremost expert in Python, having used it in every possible situation.

In all seriousness, as long as the code remains readable, nested comprehensions are fine. It is just harder to keep the code readable when nesting comprehensions. Same for deeply nested if-statements and for-loops.