How to check deque length in Python

len(queue) should give you the result, 3 in this case.

Specifically, len(object) function will call object.__len__ method [reference link]. And the object in this case is deque, which implements __len__ method (you can see it by dir(deque)).

queue= deque([])   #is this length 0 queue?

Yes it will be 0 for empty deque.

it is simple just use .qsize()example:

a=Queue()a.put("abcdef")print a.qsize() #prints 1 which is the size of queue

The above snippet applies for Queue() class of python. Thanks @rayryeng for the update.

for deque from collections we can use len() as stated here by K Z.

Yes we can check the length of queue object created from collections.

from collections import dequeclass Queue():    def __init__(self,batchSize=32):        #self.batchSie = batchSize        self._queue = deque(maxlen=batchSize)    def enqueue(self, items):        ''' Appending the items to the queue'''        self._queue.append(items)    def dequeue(self):        '''remoe the items from the top if the queue becomes full '''        return self._queue.popleft()

Creating an object of class

q = Queue(batchSize=64)q.enqueue([1,2])q.enqueue([2,3])q.enqueue([1,4])q.enqueue([1,22])

Now retrieving the length of the queue

#check the len of queueprint(len(q._queue)) #you can print the content of the queueprint(q._queue)#Can check the content of the queueprint(q.dequeue())#Check the length of retrieved item print(len(q.dequeue()))

check the results in attached screen shot

Hope this helps...