Python Deque Module Use detailed

To create a deque sequence:

From collections Import dequed = Deque ()

Deque provides a list-like method of operation:

  D = deque ()  d.append (' 1 ')  d.append (' 2 ')  d.append (' 3 ')  len (d)  d[0]  d[-1]

Output Result:

  3  ' 1 '  3 '

POPs are used on both ends:

  D = deque (' 12345 ')  len (d)  d.popleft ()  d.pop ()  D

Output Result:

  5  ' 1 '  5 '  deque ([' 2 ', ' 3 ', ' 4 '])

We can also limit the length of the deque:

D = deque (maxlen=30)

When the limit length of deque increases by more than the limit number of items, the other side of the item is automatically deleted:

  D = deque (maxlen=2)  d.append (1)  d.append (2)  D  d.append (3)  D  deque ([1, 2], maxlen=2)  Deque ([2, 3], maxlen=2)

Add items in list to deque:

  D = deque ([1,2,3,4,5])  d.extendleft ([0])  d.extend ([6,7,8])  D

Output Result:

  Deque ([0, 1, 2, 3, 4, 5, 6, 7, 8])

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