把csv文件转化为数组及数组的切片方法

import numpy
my_matrix = numpy.loadtxt(open("c:\\1.csv","rb"),delimiter=",",skiprows=0) //CSV文件转化为数组

numpy.savetxt('new.csv', my_matrix, delimiter = ',')

> arr2=np.arange(10)> arr2array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])> arr2[5:8]array([5, 6, 7])> arr[5:8]=12> arr2array([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])> arr_slice=arr2[5:8]> arr_slice[1]=12345> arr2array([  0,   1,   2,   3,   4,  12, 12345,  12,   8,   9])> arr_slice[:]=64> arr2array([ 0, 1, 2, 3, 4, 64, 64, 64, 8, 9])

> import numpy as np
> arr = np.arange(12).reshape((3, 4))
> print(arr)
[[ 0 1 2 3]
 [ 4 5 6 7]
 [ 8 9 10 11]]
> slice_one = arr[1:2, 1:3]
> print(slice_one)
[[5 6]]
> arr[:2]
array([[0, 1, 2, 3],
    [4, 5, 6, 7]])
> arr[:2,1:]
array([[1, 2, 3],
    [5, 6, 7]])