附加到python中的列表列表

Question

我正在尝试使用 for 循环将项目附加到列表列表中，但遇到 IndexError: list index out of range 错误。

class Solution:
    
    counter = [[]]
    
    def test(self):  
        i = 0
        while i < 5:
            Solution.counter[i].append(i)
            i += 1

        print(Solution.counter)

sol = Solution()
sol.test()

Answer 1

只要 i = 1，Python 就会尝试在列表中查找第二个值，但它当前为 [[0]]。所以没有第二个列表可以附加 1。但你可以这样做：

class Solution:

counter = [] # <--- Note this 

def test(self):  
    i = 0
    while i < 5:
        Solution.counter.append([i]) # <-- Appending list with i in it
        i += 1

    print(Solution.counter)

这应该有效（假设您希望 counter 成为 [[0], [1], [2], ...]，否则我弄错了）。

Answer 2

# I have checked it, its running

class Solution:
    
    counter = []
    
    def test(self):  
        i = 0
        while i < 5:
            Solution.counter.append(i)
            i += 1

        print(Solution.counter)

sol = Solution()
sol.test()