Is returning inside a 'with' statement dangerous?

Question

I need to return the contents of a file, is it fine to do this :

def foo(filePath):
    with open(filePath) as f:
        return json.load(f)

Or should I do this instead :

def foo(filePath):
    with open(filePath) as f:
        r = json.load(f)
    return r

(Of course my functions do other stuff, this is a toy model)

@CeliusStingher we don't know without more clarification from OP, but that thread is perhaps one part of the question. I assumed OP was asking broadly, i.e. are there any other issues returning like that could cause? (I'd say it's too broad as-is) — BruceWayne, Oct 21 '20 at 18:15
@BruceWayne The duplicate thread answers the question, I just wanted to be sure ```return``` doesn't somehow break context managers, and it seems like it doesn't — ice-wind, Oct 21 '20 at 18:25

score 1 · Accepted Answer · answered Oct 21 '20 at 18:03

1

Returning inside a with block is not dangerous. Write it the first way.

answered Oct 21 '20 at 18:03

John Kugelman

I assume that doing it the first way also closes `f` when it `return`s? – BruceWayne Oct 21 '20 at 18:11
2

@BruceWayne yes, that's one of the main reasons for using a context manager - it takes care of all the cleanup for you. – MattDMo Oct 21 '20 at 18:13

1 Answers1