想判断对象的属性是否存在队列的所有对象中
用语言不太容易表达，请直接看代码吧。
我想知道python语言本身是不是提供这样的功能？
python
class Queue:
"A container with a first-in-first-out (FIFO) queuing policy."
def __init__(self):
self.list = []
def push(self,item):
"Enqueue the 'item' into the queue"
self.list.insert(0,item)
def pop(self):
"""
Dequeue the earliest enqueued item still in the queue. This
operation removes the item from the queue.
"""
return self.list.pop()
def isEmpty(self):
"Returns true if the queue is empty"
return len(self.list) == 0
class A:
def __init__(self, number):
self.number = number
def main():
queue = Queue();
queue.push(A(1))
queue.push(A(2))
queue.push(A(3))
queue.push(A(4))
a = A(3)
if a.number in queue.list.number: #如何判断queue中有没有一个对象的number属性是3
print("a.number is in queue")
if __name__ == "__main__": main()
