class MyDict: def __init__(self, num=100): # 指定列表大小  self._num = num  self._lst = []  for _ in range(self._num):   self._lst.append([]) def update(self, key, value): # 添加 key-value  key_index = hash(key) % self._num  for i, (k, v) in enumerate(self._lst[key_index]):   if key == k:    self._lst[key_index][i] = [key, value]    break  else:   self._lst[key_index].append([key, value]) def get(self, key): # 根據(jù)指定的 key 彈出值  key_index = hash(key) % self._num  for k, v in self._lst[key_index]:   if k == key:    return v  else:   raise KeyError('No such {} key'.format(key)) def pop(self, key): # 根據(jù) key 彈出元素 并且刪除  key_index = hash(key) % self._num  for i, (k, v) in enumerate(self._lst[key_index]):   if k == key:    result = v    self._lst.pop(i)    return result  else:   raise KeyError('No such {} key'.format(key)) def __getitem__(self, key): # 可以通過下標(biāo)來取值  key_index = hash(key) % self._num  for k, v in self._lst[key_index]:   if k == key:    return v  else:   raise KeyError('No such {} key'.format(key)) def keys(self): # 取得所有的key  for index in range(self._num):   for k, v in self._lst[index]:    yield k def values(self): # 取得所有的 value  for index in range(self._num):   for k, v in self._lst[index]:    yield v def items(self): # 取得所有的條目  for index in range(self._num):   for item in self._lst[index]:    yield item