Python Deque
# deque -list-like container with fast appends and pops on either end
from collections import deque
queue = deque() # create deque
queue.append(2) # append right
queue.appenleft(1) # append left
queue.clear() # remove all elements --> len = 0
copy_queue = queue.copy() # create a shallow copy of the deque
queue.count(x) # count the number of deque elements equal to x
queue.extend([4, 5, 6]) # extend right by an iterable
queue.extendleft([1, 2, 3]) # extend left by an iterable
# More at: https://docs.python.org/3/library/collections.html#collections.deque
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