numpy.stack(arrays, axis=0, out=None)[source]¶Join a sequence of arrays along a new axis.
The axis parameter specifies the index of the new axis in the
dimensions of the result. For example, if axis=0 it will be the first
dimension and if axis=-1 it will be the last dimension.
New in version 1.10.0.
Each array must have the same shape.
The axis in the result array along which the input arrays are stacked.
If provided, the destination to place the result. The shape must be correct, matching that of what stack would have returned if no out argument were specified.
The stacked array has one more dimension than the input arrays.
See also
concatenateJoin a sequence of arrays along an existing axis.
splitSplit array into a list of multiple sub-arrays of equal size.
blockAssemble arrays from blocks.
Examples
>>> arrays = [np.random.randn(3, 4) for _ in range(10)]
>>> np.stack(arrays, axis=0).shape
(10, 3, 4)
>>> np.stack(arrays, axis=1).shape
(3, 10, 4)
>>> np.stack(arrays, axis=2).shape
(3, 4, 10)
>>> a = np.array([1, 2, 3])
>>> b = np.array([2, 3, 4])
>>> np.stack((a, b))
array([[1, 2, 3],
[2, 3, 4]])
>>> np.stack((a, b), axis=-1)
array([[1, 2],
[2, 3],
[3, 4]])