Python雙端隊列

雙端隊列(或兩端隊列)具有從任一端添加和刪除元素的功能。 Deque模塊是集合庫的一部分。 它具有添加和刪除可以直接用參數調用的元素的方法。 在下面的程序中，將導入collections模塊並聲明一個雙端隊列。 不需要任何類，直接使用內置的實現這些方法。

參數以下代碼實現 -

import collections
# Create a deque
DoubleEnded = collections.deque(["Mon","Tue","Wed"])
print (DoubleEnded)

# Append to the right
print("Adding to the right: ")
DoubleEnded.append("Thu")
print (DoubleEnded)

# append to the left
print("Adding to the left: ")
DoubleEnded.appendleft("Sun")
print (DoubleEnded)

# Remove from the right
print("Removing from the right: ")
DoubleEnded.pop()
print (DoubleEnded)

# Remove from the left
print("Removing from the left: ")
DoubleEnded.popleft()
print (DoubleEnded)

# Reverse the dequeue
print("Reversing the deque: ")
DoubleEnded.reverse()
print (DoubleEnded)

執行上面示例代碼，得到以下結果 -

deque(['Mon', 'Tue', 'Wed'])
Adding to the right: 
deque(['Mon', 'Tue', 'Wed', 'Thu'])
Adding to the left: 
deque(['Sun', 'Mon', 'Tue', 'Wed', 'Thu'])
Removing from the right: 
deque(['Sun', 'Mon', 'Tue', 'Wed'])
Removing from the left: 
deque(['Mon', 'Tue', 'Wed'])
Reversing the deque: 
deque(['Wed', 'Tue', 'Mon'])