数据结构3-队列

QUEUE1 
1 : class queue(object):
 2     def __init__(self):
 3         self.item=[]
 4 
 5     def is_empty(self):
 6         return self.item ==[]
 7 
 8     def size(self):
 9         return len(self.item)
10 
11     def insert(self,item):
12         self.item.insert(0,item)
13 
14     def out(self):
15         return self.item.pop()

1 if __name__=="__main__":
2     qu=queue()
3     qu.is_empty()
4     print(qu.size())
5     qu.insert("a")
6     qu.insert("b")
7     print(qu.size())
8     print(qu.out())

QUEUE2 

 1 class queue(object):
 2     def __init__(self):
 3         self.items=[]
 4 
 5     def is_empty(self):
 6         return self.items ==[]
 7 
 8     def size(self):
 9         return len(self.items)
10 
11     def add_font(self,item):
12         self.items.insert(0,item)
13 
14     def add_tail(self,item):
15         self.items.append(item)
16 
17     def remove_font(self):
18         self.items.pop(0)
19 
20     def remove_tail(self):
21         self.items.pop()

1 if __name__=="__main__":
2     de=deque()
3     print(de.size())
4     de.add_font("a")
5     de.add_font("b")
6     de.add_tail("a")
7     de.add_tail("b")
8     print(de.size())