Python Deque module Usage Details

Create a Deque sequence:

From collections import dequed = deque ()

Deque provides a list-like operation method:

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

Output result:

3 '1' 3'

Both ENDS Use pop:

D = deque ('000000') len (d) d. popleft () d. pop () d

Output result:

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

We can also limit the length of deque:

D = deque (maxlen = 30)

When a deque with a maximum length exceeds the limit, items on the other side are automatically deleted:

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

Add items in the 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])