case.py 文件源码

def __enter__(self):
        # The __warningregistry__'s need to be in a pristine state for tests
        # to work properly.
        warnings.resetwarnings()
        for v in list(values(sys.modules)):
            # do not evaluate Django moved modules and other lazily
            # initialized modules.
            if v and not _is_magic_module(v):
                # use raw __getattribute__ to protect even better from
                # lazily loaded modules
                try:
                    object.__getattribute__(v, '__warningregistry__')
                except AttributeError:
                    pass
                else:
                    object.__setattr__(v, '__warningregistry__', {})
        self.warnings_manager = warnings.catch_warnings(record=True)
        self.warnings = self.warnings_manager.__enter__()
        warnings.simplefilter('always', self.expected)
        return self