python - Python - 字符串列表列表

Question

所以，基本上我有一个队列（字符串列表列表）。现在，假设我想将“好的”附加到索引 1 处的列表中，为什么要为 Queue 中的所有列表附加它？如何仅在队列内将值附加到特定列表？

Queue = []
temp = []
Queue.append(temp) # 12 - 8
Queue.append(temp)
Queue.append(temp)
Queue[1].append('okay')
print(Queue)

[['okay'], ['okay'], ['okay']]

标签： pythonlistdata-structures

Answer 1

Because the three items in Queue are not three different empty lists: they're all temp. Thus temp, Queue[0], Queue[1] and Queue[2] are all the same object and modifying one of them has the result of modifying them all.

Try the following code instead:

Queue = []
Queue.append([])
Queue.append([])
Queue.append([])
Queue[1].append('okay')
print(Queue)