백준 10866번: 덱 (파이썬)

from collections import deque
import sys

list = deque()
n = int(sys.stdin.readline())
for i in range(n):
  t = sys.stdin.readline().rstrip().split()
  if t[0] == 'push_back':
    list.append(t[1])
  if t[0] == 'push_front':
    list.appendleft(t[1])
    
  if t[0] == 'pop_front':
    if len(list) == 0:
      print(-1)
    else:
      print(list.popleft())
  if t[0] == 'pop_back':
    if len(list) == 0:
      print(-1)
    else:
      print(list.pop())
      
  if t[0] == 'size':
    print(len(list))
  if t[0] == 'empty':
    if len(list) == 0:
      print(1)
    else:
      print(0)

  if t[0] == 'front':
    if len(list) == 0:
      print(-1)
    else:
      print(list[0])
  if t[0] == 'back':
    if len(list) == 0:
      print(-1)
    else:
      print(list[-1])