Convert an encoded module name to an unencoded source uri

def module2uri(self, module_name):
        """Convert an encoded module name to an unencoded source uri"""
        assert module_name.startswith(self.module_prefix), 'incompatible module name'
        path = module_name[len(self.module_prefix):]
        path = path.replace('&#DOT', '.')
        return path.replace('&#SEP', os.sep)