numpy.squeeze

numpy. squeeze ( a, axis=None ) [source]

Remove axes of length one from a.

Parameters

a array_like

Input data.

axis None or int or tuple of ints, optional

New in version 1.7.0.

Selects a subset of the entries of length one in the shape. If an axis is selected with shape entry greater than one, an error is raised.

Returns

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. Note that if all axes are squeezed, the result is a 0d array and not a scalar.

Raises

ValueError

If axis is not None, and an axis being squeezed is not of length 1

See also

expand_dims

The inverse operation, adding entries of length one

reshape

Insert, remove, and combine dimensions, and resize existing ones

Examples

>>> x = np.array([[[0], [1], [2]]])
>>> x.shape
(1, 3, 1)
>>> np.squeeze(x).shape
(3,)
>>> np.squeeze(x, axis=0).shape
(3, 1)
>>> np.squeeze(x, axis=1).shape
Traceback (most recent call last):
...
ValueError: cannot select an axis to squeeze out which has size not equal to one
>>> np.squeeze(x, axis=2).shape
(1, 3)
>>> x = np.array([[1234]])
>>> x.shape
(1, 1)
>>> np.squeeze(x)
array(1234)  # 0d array
>>> np.squeeze(x).shape
()
>>> np.squeeze(x)[()]
1234