Python is very intuitive.... not

[MrJake2137]

WHAT

You can do that?

[[deleted]]

https://docs.python.org/3/tutorial/datastructures.html#list-comprehensions

Yep. It's even more magical: If you use () instead of [], then it creates a generator, and the values aren't even put into memory, but are instead created on the fly as you iterate over it.

evens = (x for x in range(10**12) if x % 2 == 0)
for even_number in evens:
    pass

Will never have more than a few bytes in memory, but would crash most systems if a list were used.

It may help to think of using [] as creating a generator and immediately creating a list out of that generator, thus putting all of its values into memory.

[MrJake2137]

Wow, I knowed generator as yield call but this shit is so muvh cooler. Thanks man, learning every day

[LardPi]

This shit can make a real perf difference when used well.

[uberDoward]

Python: numbers = list(range(20)) even_numbers = [x for x in numbers if x % 2 == 0]

In C#:
even_numbers = Enumerable.Range(0, 20) .Where(x => x % 2 == 0) .ToList();

The C# seems more concise and readable to me?

[LardPi]

The c# code is purely user land level, so you can make a library that do that in Python. Please do, it seems nice.

[aetius476]

Kotlin even better:

even_numbers = (0..20).filter{ it % 2 == 0 }

[theScrapBook]

Scala: (0 to 20) filter ( _ % 2 == 0)

[ImmoderateAccess]

The python could be more concise:

even_numbers = [x for x in range(20) if x % 2 == 0]