Python: TypeError:列表索引必须是整数，而不是str。

I'm going to do Matrix Addition on Python.(Not finish). But it shows an error.

我将在Python上做矩阵加法。(没有完成)。但它显示了一个错误。

m, n = (int(i) for i in raw_input().split())
a = [[0 for i in range(m)] for j in range(n)]
b = [[0 for i in range(m)] for j in range(n)]
c = []
total = []

for i in range(m):
    x = raw_input()
    for j in range(n):
        value = [int(i) for i in x.split()]
    c[i][j] = a[i][j]
    #c.append(value)
print a
for i in c:
    print i

I want to input

我想输入

3 3 <-- matrix dimensional m*n

3 3 <——矩阵维m*n。

1 2 3 >

3 2 1 > matrix A

3 2 1 >矩阵A。

1 3 2 >

1 2 3 >

1 1 1 >

1 1 1 > matrix B

1 >矩阵B。

1 1 1 >

and shows as

和显示

2 3 4 >

4 3 2 > matrix A + B

4 3 2 >矩阵A + B。

2 4 3 >

5 个解决方案

#1

You are using i in your outer for loop, and it is an int. Then in the loop you have:

你在你的外部循环中使用i，它是一个整数，然后在循环中你有:

value = [int(i) for i in x.split()]

which makes i a string (which is what split returns). Maybe you think there is some sort of scoping inside [ ]? There isn't. You have a name collision, change one of them.

它使我成为一个字符串(这就是split返回)。也许你认为[]里面有某种范围的范围?没有。你有一个名字碰撞，改变其中一个。

#2

You are using same variable in inner for loop.

在内部循环中使用相同的变量。

for i in range(m):
    x = raw_input()
    for j in range(n):
        # variable i is refering to outer loop
        value = [int(p) for p in x.split()]
    c[i][j] = a[i][j]
    #c.append(value)
print a
for i in c:
    print i

#3

Beyond the first two answers you'll have a problem with this statement:

除了前两个答案，你会有一个问题:

c[i][j] = a[i][j]

When the loop starts i will be 0 and that's so far OK, but c is an empty list and has no iterable at the first position so c[0][0] will return an error. Get rid of it and uncomment the following line:

当循环开始时，我将是0，到目前为止还可以，但是c是一个空列表，在第一个位置上没有迭代，所以c[0][0]将返回一个错误。去掉它，取消注释:

#c.append(value)

EDIT:

编辑:

Your code won't return what you want. You'd better make something like this to create a matrix with the given sides:

你的代码不会返回你想要的。你最好做一些这样的事情来创建一个矩阵，它有一个给定的边:

for i in range(m):
    d = []
    for j in range(n):
        x = raw_input()
        d.append(int(x))
     c.append(d)

If you have 3 for both m and n, then you will create matrix with sides 3 x 3 saved in the variable c. In this way you don't have to split the user input. The user can give a number at a time. And you could even change the following line:

如果你对m和n都有3，那么你就会创建矩阵，在变量c中保存3 x 3，这样你就不需要分割用户输入。用户可以一次给出一个数字。你甚至可以改变下一行:

x = raw_input()

to:

x = raw_input("{0}. row, {1}. column: ".format(i+1, j+1))

Try it out!

试一下!

#4

import time
m, n = (int(i) for i in raw_input().split())
a = []
b = []
total = [[0 for i in range(n)] for j in range(m)]

for i in range(m):
    x = raw_input()
    for j in range(n):
        value = [int(i) for i in x.split()]
    a.append(value)
#print a


for i in range(m):
    x = raw_input()
    for j in range(n):
        value = [int(i) for i in x.split()]
    b.append(value)
#print b


for i in range(m):
    for j in range(n):
        total[i][j] = a[i][j] + b[i][j]


for i in total:
    print ' '.join(map(str, i))
time.sleep(2)

OK! I just figured it out! Thank you

好的!我刚想出来了!谢谢你！

#5

you can also hit this error if you declare an int and treat it like a dict

如果您声明一个int并将其视为一个命令，您也可以点击这个错误。

>>> a = []
>>> a['foo'] = 'bar'
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: list indices must be integers, not str

#1