Python collections - deque

Deque is another powerful data structure from collections. It implements all feature of Double-ended_queue.Lets see an example how to use it.

All source code available on github

from collections import deque

dq = deque([1,2,3])
print dq

dq.append(4) # add end of the deque
dq.appendleft(5) # add beginning of the deque

print dq

print dq.pop()
print dq.popleft()
print dq

dq.extend([22,33,44]) # add multiple element to end of existing deque
dq.extendleft([444,333]) # add multiple element to beginning of existing deque
print dq

print 22 in dq # search in deque

dq.rotate(1)
print "Right rotate:",dq
dq.rotate(-1)
print "Left rotate:",dq

Output:

deque([1, 2, 3])
deque([5, 1, 2, 3, 4])
4
5
deque([1, 2, 3])
deque([333, 444, 1, 2, 3, 22, 33, 44])
True
Right rotate: deque([44, 333, 444, 1, 2, 3, 22, 33])
Left rotate: deque([333, 444, 1, 2, 3, 22, 33, 44])