doctest.py 文件源码

def _normalize_module(module, depth=2):
    """
    Return the module specified by `module`.  In particular:
      - If `module` is a module, then return module.
      - If `module` is a string, then import and return the
        module with that name.
      - If `module` is None, then return the calling module.
        The calling module is assumed to be the module of
        the stack frame at the given depth in the call stack.
    """
    if inspect.ismodule(module):
        return module
    elif isinstance(module, (str, unicode)):
        return __import__(module, globals(), locals(), ["*"])
    elif module is None:
        return sys.modules[sys._getframe(depth).f_globals['__name__']]
    else:
        raise TypeError("Expected a module, string, or None")