배열 다루기 | 요소 삭제(Numpy.delete)

 

 

 

 

배열 요소 삭제 함수(Delete Function)

numpy.delete(arr, obj, axis=None)

 

지정한 Index의 요소를 삭제시켜주는 함수입니다.

▪Parameters

     ‣  arr : 입력 배열,

     ‣  obj : 값 추가 전 인덱스를 지정하는 개체 삽입(slice or Index),

     ‣  axis : 축 설정(선택 사항), 계산이 진행되는 축 설정

 

     ‣  out : ndarray, 삭제된 배열 출력 값(axis 지정이 없다면 1D Array 형태로 출력)

 

 

예제(Example)

<Example 01>

import numpy as np

a = np.arange(1, 10, 1)
print('Initial np values : ', a)

a = np.delete(a, 0)
print('1st delete data : ', a)
a = np.delete(a, 1)
print('2nd delete data : ', a)
a = np.delete(a, 2)
print('3rd delete data : ', a)
a = np.delete(a, 3)
print('4th delete data : ', a)
a = np.delete(a, 4)
print('5th delete data : ', a)

Result

nitial np values :  [1 2 3 4 5 6 7 8 9]
1st delete data :  [2 3 4 5 6 7 8 9]
2nd delete data :  [2 4 5 6 7 8 9]
3rd delete data :  [2 4 6 7 8 9]
4th delete data :  [2 4 6 8 9]
5th delete data :  [2 4 6 8]

 

<Example 02>

import numpy as np

a = np.array([[1, 2, 3],[4, 5, 6], [7, 8, 9]])

a = np.delete(a, 1, 0)
print('delete data from Axis = 0 : ')
print(a)

a = np.delete(a, 1, 1)
print('delete data from Axis = 1 : ')
print(a)

Result

delete data from Axis = 0 : 
[[1 2 3]
 [7 8 9]]
delete data from Axis = 1 :
[[1 3]
 [7 9]]

 

<Example 03>

import numpy as np

a = np.array([[1, 2, 3],[4, 5, 6], [7, 8, 9]])

a = np.delete(a, np.s_[::2], 0)
print('delete data from Axis = 0 : ')
print(a)

a = np.array([[1, 2, 3],[4, 5, 6], [7, 8, 9]])

a = np.delete(a, np.s_[::2], 1)
print('delete data from Axis = 1 : ')
print(a)

Result

delete data from Axis = 0 : 
[[4 5 6]]
delete data from Axis = 1 :
[[2]
 [5]
 [8]]

Numpy 함수 모음

 

 

 

 

 

 

 

 

 

※ 이 글이 도움이 되었다면 "👆🏻구독"과 "🤍공감" 버튼을 클릭해주세요. 클릭 한번이 글 쓰는데 큰 힘이 됩니다.