Function warnings_state

Lib/test/test_warnings/__init__.py:36–63

Use a specific warnings implementation in warning_tests.

(module)

@contextmanager
def warnings_state(module):
    """Use a specific warnings implementation in warning_tests."""
    global __warningregistry__
    for to_clear in (sys, warning_tests):
        try:
            to_clear.__warningregistry__.clear()
        except AttributeError:
            pass
    try:
        __warningregistry__.clear()
    except NameError:
        pass
    original_warnings = warning_tests.warnings
    if module._use_context:
        saved_context, context = module._new_context()
    else:
        original_filters = module.filters
        module.filters = original_filters[:]
    try:
        module.simplefilter("once")
        warning_tests.warnings = module
        yield
    finally:
        warning_tests.warnings = original_warnings
        if module._use_context:
            module._set_context(saved_context)
        else:
            module.filters = original_filters


class TestWarning(Warning):