CODEWITHSUNDEEP
pythonnumpy
user644745
user644745

Reputation: 5713

remove a specific column in numpy

>>> arr = np.array([[1,2,3,4], [5,6,7,8], [9,10,11,12]])
>>> arr
array([[ 1,  2,  3,  4],
       [ 5,  6,  7,  8],
       [ 9, 10, 11, 12]])

I am deleting the 3rd column as 

>>> np.hstack(((np.delete(arr, np.s_[2:], 1)),(np.delete(arr, np.s_[:3],1))))
array([[ 1,  2,  4],
       [ 5,  6,  8],
       [ 9, 10, 12]])

Are there any better way ? Please consider this to be a novice question.

Upvotes: 25

Views: 32172

Answers (3)

Akavall
Akavall

Reputation: 86248

If you ever want to delete more than one columns, you just pass indices of columns you want deleted as a list, like this:

>>> a = np.arange(12).reshape(3,4)
>>> a
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [ 8,  9, 10, 11]])
>>> np.delete(a, [1,3], axis=1)
array([[ 0,  2],
       [ 4,  6],
       [ 8, 10]])

Upvotes: 47

Fredrik Pihl
Fredrik Pihl

Reputation: 45672

Something like this:

In [7]: x = range(16)

In [8]: x = np.reshape(x, (4, 4))

In [9]: x
Out[9]: 
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [ 8,  9, 10, 11],
       [12, 13, 14, 15]])

In [10]: np.delete(x, 1, 1)
Out[10]: 
array([[ 0,  2,  3],
       [ 4,  6,  7],
       [ 8, 10, 11],
       [12, 14, 15]])

Upvotes: 2

jamylak
jamylak

Reputation: 133604

>>> import numpy as np
>>> arr = np.array([[1,2,3,4], [5,6,7,8], [9,10,11,12]])
>>> np.delete(arr, 2, axis=1)
array([[ 1,  2,  4],
       [ 5,  6,  8],
       [ 9, 10, 12]])

Upvotes: 8

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