support.py 文件源码

def requires(resource, msg=None):
    """Raise ResourceDenied if the specified resource is not available.

    If the caller's module is __main__ then automatically return True.  The
    possibility of False being returned occurs when regrtest.py is
    executing.
    """
    if resource == 'gui' and not _is_gui_available():
        raise unittest.SkipTest("Cannot use the 'gui' resource")
    # see if the caller's module is __main__ - if so, treat as if
    # the resource was set
    if sys._getframe(1).f_globals.get("__name__") == "__main__":
        return
    if not is_resource_enabled(resource):
        if msg is None:
            msg = "Use of the %r resource not enabled" % resource
        raise ResourceDenied(msg)