Classe « clear_and_catch_warnings »

Informations générales

Héritage

builtins.object
    catch_warnings
        clear_and_catch_warnings

Définition

class clear_and_catch_warnings(catch_warnings):

help(clear_and_catch_warnings)

Context manager that resets warning registry for catching warnings

Warnings can be slippery, because, whenever a warning is triggered, Python
adds a ``__warningregistry__`` member to the *calling* module.  This makes
it impossible to retrigger the warning in this module, whatever you put in
the warnings filters.  This context manager accepts a sequence of `modules`
as a keyword argument to its constructor and:

* stores and removes any ``__warningregistry__`` entries in given `modules`
  on entry;
* resets ``__warningregistry__`` to its previous state on exit.

This makes it possible to trigger any warning afresh inside the context
manager without disturbing the state of warnings outside.

For compatibility with Python 3.0, please consider all arguments to be
keyword-only.

Parameters
----------
record : bool, optional
    Specifies whether warnings should be captured by a custom
    implementation of ``warnings.showwarning()`` and be appended to a list
    returned by the context manager. Otherwise None is returned by the
    context manager. The objects appended to the list are arguments whose
    attributes mirror the arguments to ``showwarning()``.
modules : sequence, optional
    Sequence of modules for which to reset warnings registry on entry and
    restore on exit. To work correctly, all 'ignore' filters should
    filter by one of these modules.

Examples
--------
>>> import warnings
>>> with np.testing.clear_and_catch_warnings(
...         modules=[np._core.fromnumeric]):
...     warnings.simplefilter('always')
...     warnings.filterwarnings('ignore', module='np._core.fromnumeric')
...     # do something that raises a warning but ignore those in
...     # np._core.fromnumeric