python - python 错误: name '...' is not defined

Question

我正在使用列表来存储一些值。

示例代码:

for i in range(3):
  print i
  lst[i] = i+1
  print lst[i]

但是我收到这样的错误:

lst[i] = i+1
NameError: name 'lst' is not defined

Python中数组需要初始化吗？我的代码有什么问题？

Answer 1

这是您的代码:

    for i in range(3):
        print i
        lst[i] = i+1
        print lst[i]

有两个问题

1- you havn't initialize your list, the computer doesn't know yet that you are working with a list (like you do in programs where u keep track of a counter variable like count = count + i because it must have a seed value to start with)
2- you cannot append elements to a list with the assignment operator, use the append function for that.

所以这是正确的代码:

    lst = []
    for i in range(3):
        print(i)
        lst.append(i+1)
    print(lst[i])

输出: 0 1 2 3