common.py 文件源码

def relto(self, relpath):
        """ return a string which is the relative part of the path
        to the given 'relpath'.
        """
        if not isinstance(relpath, (str, PathBase)):
            raise TypeError("%r: not a string or path object" %(relpath,))
        strrelpath = str(relpath)
        if strrelpath and strrelpath[-1] != self.sep:
            strrelpath += self.sep
        #assert strrelpath[-1] == self.sep
        #assert strrelpath[-2] != self.sep
        strself = self.strpath
        if sys.platform == "win32" or getattr(os, '_name', None) == 'nt':
            if os.path.normcase(strself).startswith(
               os.path.normcase(strrelpath)):
                return strself[len(strrelpath):]
        elif strself.startswith(strrelpath):
            return strself[len(strrelpath):]
        return ""