Python antipattern: Close in finally

Don’t do this:

thing = Thing()
try:
    thing.do_stuff()
finally:
    thing.close()

Do do this:

from contextlib import closing

with closing(Thing()) as thing:
    thing.do_stuff()

Why is the second better? Using contextlib.closing() ties closing the item to its creation. These baby examples are about equally easy to reason about, with only a single line in the try block, but consider what happens ifwhen more lines get added in future? In the first example, the close moves away, potentially offscreen, but that doesn’t happen in the second.