__init__.py 文件源码

def issue_warning(*args, **kw):
    level = 1
    g = globals()
    try:
        # find the first stack frame that is *not* code in
        # the pkg_resources module, to use for the warning
        while sys._getframe(level).f_globals is g:
            level += 1
    except ValueError:
        pass
    warnings.warn(stacklevel=level + 1, *args, **kw)