在Python中更改len()函数

时间:2017-05-06 16:52:38

标签: python python-2.7

之前,我的代码中有这个向量:

x = [
[0.72,0.82],
[0.91,-0.69],
[0.03,0.93],
[0.12,0.25],
[0.96,0.47],
[0.8,-0.75]
]

这个 正常工作:

for k in range(1,10):

    for i in range(0,len(x)):
        sum = 0

        for j in range(0,len(x[i])):
            sum += x[i][j] * w[j]

我必须在矢量中进行更改:

x = [
[0.72,0.82,-1],
[0.91,-0.69,-1],
[0.03,0.93,-1],
[0.12,0.25,-1],
[0.96,0.47,-1],
[0.8,-0.75,-1]
]

从这个意义上讲,我意识到我需要在 len(x [i])中进行修改,以便之前的结果与现在相同,我试着 len (x [0] [1]),但它不起作用,我该怎么办?

1 个答案:

答案 0 :(得分:0)

然后j从0变为1。 (或者如果你想,“len(x [i]) - 1”)

for k in range(1,10):

    for i in range(0,len(x)):
        sum = 0

        for j in range(2):
            sum += x[i][j] * w[j]