Unlink a new array from older one: python

Question

My problem is as follows. I have a 2D array. From the 2D array I take out one row as an 1D array and work with it and make changes, but it also changes the original entries in the 2D array, but I want them to remain constant. How do I solve this in python?

possible duplicate of [How to clone a list in python?](http://stackoverflow.com/questions/2612802/how-to-clone-a-list-in-python) — Rohit Jain, Dec 01 '12 at 21:55
@RohitJain: That question is about `list`, and this one is about `ndarray`. — NPE, Dec 01 '12 at 21:57
@NPE.. Yeah I noticed that. But I thought it can be done in the same way. Couldn't it? — Rohit Jain, Dec 01 '12 at 21:59

score 3 · Answer 1 · answered Dec 01 '12 at 21:55

You could use ndarray.copy():

In [17]: A = array([[1, 1], [3, 2], [-4, 1]])

In [18]: b = A[1].copy()

In [19]: b
Out[19]: array([3, 2])

In [20]: b[0] = 4

In [21]: b
Out[21]: array([4, 2])

In [22]: A
Out[22]: 
array([[ 1,  1],
       [ 3,  2],
       [-4,  1]])

As you can see, A[1] remains unchanged.

Unlink a new array from older one: python

1 Answers1