1. class CQueue(object):
    3.     def __init__(self):
    4.         self.stk_in = []
    5.         self.stk_out = []
    7.     def appendTail(self, value):
    8.         """
    9.         :type value: int
    10.         :rtype: None
    11.         """
    12.         self.stk_in.append(value)
    14.     def deleteHead(self):
    15.         """
    16.         :rtype: int
    17.         """
    18.         if self.stk_out == []:
    19.             while self.stk_in != []:
    20.                 self.stk_out.append(self.stk_in.pop())
    21.         if self.stk_out != []:
    22.             while self.stk_out != []:
    23.                 return self.stk_out.pop()
    24.         else:
    25.             return -1