pg.py 文件源码

def __init__(self, *args, **kw):
            if len(args) > 1 or kw:
                raise TypeError
            items = args[0] if args else []
            if isinstance(items, dict):
                raise TypeError
            items = list(items)
            self._keys = [item[0] for item in items]
            dict.__init__(self, items)
            self._read_only = True
            error = self._read_only_error
            self.clear = self.update = error
            self.pop = self.setdefault = self.popitem = error