python报错 list indices must be integers or slices, not tuple

报错程序

import numpy as np

b = [[2,3,4]
     [2,3,4]]
c = [[1,2,3]
     [1,2,3]]
B = [np.sum(np.abs(a - c)) for a in b]

print(B)

# 报错行：b = [[2,3,4]
# TypeError: list indices must be integers or slices, not tuple
# 列表索引必须是整数或片，而不是元组

列表索引必须是整数或片，而不是元组

---

下面是修改过程：
1 修改b和c。
修改后程序报错改变

import numpy as np

b = [[2,3,4],   # 注意加逗号
     [2,3,4]]
c = [[1,2,3],
     [1,2,3]]
B = [np.sum(np.abs(a - c)) for a in b]

print(B)

# 报错行：B = [np.sum(np.abs(a - c)) for a in b]
# TypeError: unsupported operand type(s) for -: 'list' and 'list'
# 减号不能用于list和list之间

注意：b的以下写法会报错

b = [[2,3,4]
     [2,3,4]]
     
b = [[2,3,4] [2,3,4]]

b = [[2,3,4];
    [2,3,4]]
    
b = [[2,3,4]; [2,3,4]]

b的以下写法正确（要用逗号！）

b = [[2,3,4],   
     [2,3,4]]
     
b = [[2,3,4], [2,3,4]]

2 增加numpy的array，用numpy里的array转化成元组 ： dataSet=np.array(dataSet)
修改后程序：

import numpy as np

b = [[2,3,4],
    [2,3,4]]
c = [[1,2,3],
     [1,2,3]]

# add     
b = np.array(b)
c = np.array(c)

B = [np.sum(np.abs(a - c)) for a in b]

print(B)

# 输出
# [6, 6]

其他解决方法：

• 将dataSet转化为矩阵：mat(dataSet)