What use does the with statement in python have in the standard library apart from interacting with files?

Question

I am aware that the with statement allows context managers to 'clean up after themselves', but other than the well known

with open("text.txt") as f:
    data = f.read()

what uses does the with statement have utilizing just the standard library, without creating custom context managers?

To be clear: it sounds like this is similar to asking what context managers are provided by the standard library? — David Z, Apr 26 '15 at 15:44
@DavidZ yes, unless there are uses for `with` that somehow do not involve context managers. — enigma, Apr 26 '15 at 15:45
So look through the standard library to see which modules define context managers. — chepner, Apr 26 '15 at 15:46
It might be easiest to just grep the source for `__enter__` or `@contextmanager`. — Veedrac, Apr 26 '15 at 15:48
ah, apologies for the duplicate. I did search before, honest! — enigma, Apr 26 '15 at 15:52

jwilner · Answer 1 · 2015-04-26T15:49:39.583

1

At the very least, it's useful in Python threading (although geez, Python threading ain't ever that useful). https://docs.python.org/2/library/threading.html#using-locks-conditions-and-semaphores-in-the-with-statement

Oh, and pool executors.

with concurrent.futures.ProcessPoolExecutor(max_workers=10) as executor:
    for _ in range(10):
        executor.submit(some_func)

edited Apr 26 '15 at 15:49

answered Apr 26 '15 at 15:44

jwilner

1 Answers1