View and Copy¶

In [1]:
%pip install numpy
import numpy as np

Requirement already satisfied: numpy in /home/samrat/Documents/numpy-torch-tutorials/venv/lib/python3.8/site-packages (1.24.4)
Note: you may need to restart the kernel to use updated packages.
In [2]:
squid = np.arange(12).reshape(3,-1)
squid
Out[2]:
array([[ 0,  1,  2,  3],
       [ 4,  5,  6,  7],
       [ 8,  9, 10, 11]])
In [5]:
ward = squid[:, :2]
ward
Out[5]:
array([[0, 1],
       [4, 5],
       [8, 9]])
In [7]:
sponge = squid[:, [0,1]]
sponge
Out[7]:
array([[0, 1],
       [4, 5],
       [8, 9]])
In [8]:
sponge[0, 0] = 100
sponge, squid, ward
Out[8]:
(array([[100,   1],
        [  4,   5],
        [  8,   9]]),
 array([[ 0,  1,  2,  3],
        [ 4,  5,  6,  7],
        [ 8,  9, 10, 11]]),
 array([[0, 1],
        [4, 5],
        [8, 9]]))
In [9]:
ward[0, 0] = 100
squid, ward
Out[9]:
(array([[100,   1,   2,   3],
        [  4,   5,   6,   7],
        [  8,   9,  10,  11]]),
 array([[100,   1],
        [  4,   5],
        [  8,   9]]))
In [10]:
squid.__array_interface__
Out[10]:
{'data': (31710704, False),
 'strides': None,
 'descr': [('', '<i8')],
 'typestr': '<i8',
 'shape': (3, 4),
 'version': 3}
In [11]:
sponge.__array_interface__
Out[11]:
{'data': (41664864, False),
 'strides': (8, 24),
 'descr': [('', '<i8')],
 'typestr': '<i8',
 'shape': (3, 2),
 'version': 3}
In [12]:
ward.__array_interface__
Out[12]:
{'data': (31710704, False),
 'strides': (32, 8),
 'descr': [('', '<i8')],
 'typestr': '<i8',
 'shape': (3, 2),
 'version': 3}
In [13]:
np.shares_memory(squid, ward)
Out[13]:
True
In [14]:
np.shares_memory(squid, sponge)
Out[14]:
False
In [15]:
squid[:, :2].copy()
Out[15]:
array([[100,   1],
       [  4,   5],
       [  8,   9]])