Pylint prefers list comprehension over filter...

[Stephen Hansen]

On Thu, May 5, 2016, at 06:26 PM, Christopher Reimer wrote:
> Which is one is correct (Pythonic)? Or does it matter?

First, pylint is somewhat opinionated, and its default options shouldn't
be taken as gospel. There's no correct: filter is fine.

That said, the general consensus is, I believe, that list comprehensions
are good, and using them is great.

In your case, though, I would not use a list comprehension. I'd use a
generator comprehension. It looks almost identical:

    ''.join(x for x in string if x.isupper())

The difference is, both filter and your list comprehension *build a
list* which is not needed, and wasteful. The above skips building a
list, instead returning a generator, and join pulls items out of it one
at a time as it uses them. No needlessly creating a list only to use it
and discard it.

-- 
Stephen Hansen
  m e @ i x o k a i  . i o