debugging.py 文件源码

def _postmortem_traceback(excinfo):
    # A doctest.UnexpectedException is not useful for post_mortem.
    # Use the underlying exception instead:
    from doctest import UnexpectedException
    if isinstance(excinfo.value, UnexpectedException):
        return excinfo.value.exc_info[2]
    else:
        return excinfo._excinfo[2]