Merge pull request wangzheng0822#257 from alouhaha/patch-2

remove wrong code, add dequene() return

Author: wangzheng0822

python/09_queue/array_queue.py

@@ -21,11 +21,7 @@ def enqueue(self, item: str) -> bool:
  return False
  else:
  for i in range(0, self._tail - self._head):
-<<<<<<< HEAD
- self._data[i] = self._items[i + self._head]
-=======
  self._items[i] = self._items[i + self._head]
->>>>>>> upstream/master
  self._tail = self._tail - self._head
  self._head = 0
 
@@ -38,6 +34,8 @@ def dequeue(self) -> Optional[str]:
  item = self._items[self._head]
  self._head += 1
  return item
+ else:
+ return None
 
  def __repr__(self) -> str:
  return " ".join(item for item in self._items[self._head : self._tail])