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NumPy Array manipulation: squeeze() function

numpy.squeeze() function

The squeeze() function is used to remove single-dimensional entries from the shape of an array.

Syntax:

numpy.squeeze(a, axis=None)
NumPy manipulation: squeeze() function

Version: 1.15.0

Parameter:

Name Description Required /
Optional
a Input data. Required
axis Selects a subset of the single-dimensional entries in the shape. If an axis is selected with shape entry greater than one, an error is raised. Optional

Return value:

squeezed [ndarray] The input array, but with all or a subset of the dimensions of length 1 removed. This is always a itself or a view into a.

Raises: ValueError - If axis is not None, and an axis being squeezed is not of length 1

Example-1: numpy.squeeze() function

>>> import numpy as np
>>> a = np.array([[[0], [2], [4]]])
>>> a.shape
(1, 3, 1)
>>> np.squeeze(a).shape
(3,)

Pictorial Presentation:

NumPy manipulation: squeeze() function

Example-2: numpy.squeeze() function

>>> import numpy as np
>>> a = np.array([[[0], [2], [4]]])
>>> np.squeeze(a, axis=0).shape
(3, 1)
>>> np.squeeze(a, axis=1).shape
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python3.6/dist-packages/numpy/core/fromnumeric.py", line 1201, in squeeze
    return squeeze(axis=axis)
ValueError: cannot select an axis to squeeze out which has size not equal to one
>>> np.squeeze(a, axis=2).shape
(1, 3)

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