Proposed check: use suppress context manager

Instead of

try:
    do_something()
except RuntimeError:
    pass

suggest using

with contextlib.suppress(RuntimeError):
    do_something()

What do you think?

[joaoe]

I did comment on the subtle bugs it might introduce, but there is another question: is bugbear supposed to be a tool to help detect bugs or to check coding style/conventions ? Is there anything inherently wrong about except: pass ? Does suppress fix anything ? In the end, using suppress is more of a style choice, and perhaps not so relevant for bugbear.

[orlnub123]

Django had a ticket a while back to replace all the try ... except ...: pass blocks with contextlib.suppress(...): ..., but it was reverted due to performance concerns.

Even the people commenting on the issue that introduced it were indecisive about it. I think Ezio put it best:

This saves two lines, but makes the code less explicit, it can’t be used for try/except/else or try/except/except, it requires an extra import, the implementation is simple enough that it doesn’t necessary need to be in the stdlib, it might encourage bad style, and it’s slower.