[issue33146] contextlib.suppress should capture exception for inspection and filter on substrings

[Jason R. Coombs]

New submission from Jason R. Coombs <jaraco at jaraco.com>:

I propose the following expansion of the interface of contextlib.suppress. Currently, when entering the context, suppress returns None. Instead, it could return an object that provides some detail about the exception.

Inspiration for an implementation exists in pytest (https://github.com/pytest-dev/pytest/blob/ff3d13ed0efab6692a07059b1d61c53eec6e0412/_pytest/python_api.py#L627), capturing the commonly-encountered use-cases, where one wishes to capture, suppress, and then act on a subset of exceptions, allowing others to raise normally.

In [py-181](https://github.com/pytest-dev/py/pull/181), I suggest exposing this functionality generally, but others had an instinct similar to mine - that perhaps the stdlib should be providing this interface.

In addition to saving the exception for inspection, the pytest implementation also allows a "message" to be supplied (for those exceptions where only some subset of the class of Exception is suppressed).

I present this concept here for consideration and feedback. Can contextlib.suppress be expanded with such an interface?

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components: Library (Lib)
messages: 314461
nosy: jason.coombs
priority: normal
severity: normal
status: open
title: contextlib.suppress should capture exception for inspection and filter on substrings
versions: Python 3.8

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue33146>
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