Python numpy.insert()用法及代码示例

关于：
numpy.insert(数组，对象，值，轴=无)：沿提到的轴在给定索引之前插入值。
参数：

array   : [array_like]Input array. 
object  : [int, array of ints]Sub-array with the index or indices before 
     which values is inserted
values  : [array_like]values to be added in the arr. Values should be 
     shaped so that arr[...,obj,...] = values. If the type of values is different from 
     that of arr, values is converted to the type of arr
axis    : Axis along which we want to insert the values. By default, it 
     object is applied to flattened array

返回：

An copy of array with values being inserted as per the mentioned object along a given axis.

代码1：从一维数组中删除

# Python Program illustrating 
# numpy.insert() 
  
import numpy as geek 
  
#Working on 1D 
arr = geek.arange(5) 
print("1D arr : \n", arr) 
print("Shape : ", arr.shape) 
  
# value = 9 
# index = 1    
# Insertion before first index 
a = geek.insert(arr, 1, 9) 
print("\nArray after insertion : ", a) 
print("Shape : ", a.shape) 
  
  
# Working on 2D array  
arr = geek.arange(12).reshape(3, 4) 
print("\n\n2D arr : \n", arr) 
print("Shape : ", arr.shape) 
  
a = geek.insert(arr, 1, 9, axis = 1) 
print("\nArray after insertion : \n", a) 
print("Shape : ", a.shape)

输出：

1D arr : 
 [0 1 2 3 4]
Shape :  (5,)

Array after insertion :  [0 9 1 2 3 4]
Shape :  (6,)


2D arr : 
 [[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]]
Shape :  (3, 4)

Array after insertion : 
 [[ 0  9  1  2  3]
 [ 4  9  5  6  7]
 [ 8  9  9 10 11]]
Shape :  (3, 5)

代码2：使用标量

# Python Program illustrating 
# numpy.insert() 
  
import numpy as geek 
  
# Working on 2D array  
arr = geek.arange(12).reshape(3, 4) 
print("2D arr : \n", arr) 
print("Shape : ", arr.shape) 
  
# Working with Scalars 
a = geek.insert(arr, [1], [[6],[9],], axis = 0) 
print("\nArray after insertion : \n", a) 
print("Shape : ", a.shape) 
  
# Working with Scalars 
a = geek.insert(arr, [1], [[8],[7],[9]], axis = 1) 
print("\nArray after insertion : \n", a) 
print("Shape : ", a.shape)

输出：

2D arr : 
 [[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]]
Shape :  (3, 4)

Array after insertion : 
 [[ 0  1  2  3]
 [ 6  6  6  6]
 [ 9  9  9  9]
 [ 4  5  6  7]
 [ 8  9 10 11]]
Shape :  (5, 4)

Array after insertion : 
 [[ 0  8  1  2  3]
 [ 4  7  5  6  7]
 [ 8  9  9 10 11]]
Shape :  (3, 5)

代码3：在不同点插入

# Python Program illustrating 
# numpy.insert() 
  
import numpy as geek 
  
#Working on 1D 
arr = geek.arange(6).reshape(2, 3) 
print("1D arr : \n", arr) 
print("Shape : ", arr.shape) 
  
# value = 9 
# index = 1    
# Insertion before first index 
a = geek.insert(arr, (2, 4), 9) 
print("\nInsertion at two points : ", a) 
print("Shape : ", a.shape) 
  
  
# Working on 2D array  
arr = geek.arange(12).reshape(3, 4) 
print("\n\n2D arr : \n", arr) 
print("Shape : ", arr.shape) 
a = geek.insert(arr, (0, 3), 66, axis = 1) 
print("\nInsertion at two points : \n", a) 
print("Shape : ", a.shape)

输出：

1D arr : 
 [[0 1 2]
 [3 4 5]]
Shape :  (2, 3)

Insertion at two points :  [0 1 9 2 3 9 4 5]
Shape :  (8,)


2D arr : 
 [[ 0  1  2  3]
 [ 4  5  6  7]
 [ 8  9 10 11]]
Shape :  (3, 4)

Insertion at two points : 
 [[66  0  1  2 66  3]
 [66  4  5  6 66  7]
 [66  8  9 10 66 11]]
Shape :  (3, 6)

参考文献：
https://docs.scipy.org/doc/numpy/reference/generated/numpy.insert.html#numpy.insert

注意：
这些代码无法在online-ID上运行。请在您的系统上运行它们以探索其工作原理。

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注：本文由纯净天空筛选整理自 numpy.insert() in Python。非经特殊声明，原始代码版权归原作者所有，本译文未经允许或授权，请勿转载或复制。