NumPy 数组操作 numpy.delete

此函数从输入数组中删除指定的子数组，并返回一个新数组。与insert()函数一样，如果未使用axis参数，则输入数组会被展平。该函数接受以下参数：

Numpy.delete(arr, obj, axis)

其中，

序号	参数和描述
1	arr 输入数组
2	obj 可以是一个切片、一个整数或一个整数数组，表示要从输入数组中删除的子数组
3	axis 要删除给定子数组的轴。如果未给出，则将 arr 拉平

示例

import numpy as np 
a = np.arange(12).reshape(3,4) 

print 'First array:' 
print a 
print '\n'  

print 'Array flattened before delete operation as axis not used:' 
print np.delete(a,5) 
print '\n'  

print 'Column 2 deleted:'  
print np.delete(a,1,axis = 1) 
print '\n'  

print 'A slice containing alternate values from array deleted:' 
a = np.array([1,2,3,4,5,6,7,8,9,10]) 
print np.delete(a, np.s_[::2])

它的输出将如下所示 –

First array:
[[ 0 1 2 3]
 [ 4 5 6 7]
 [ 8 9 10 11]]

Array flattened before delete operation as axis not used:
[ 0 1 2 3 4 6 7 8 9 10 11]

Column 2 deleted:
[[ 0 2 3]
 [ 4 6 7]
 [ 8 10 11]]

A slice containing alternate values from array deleted:
[ 2 4 6 8 10]