numpy split()

numpy. split (ary, indices_or_sections, axis=0)[source]

Split an array into multiple sub-arrays.

将一个array分成多个子array

Parameters:	ary : ndarray Array to be divided into sub-arrays. indices_or_sections : int or 1-D array If indices_or_sections is an integer, N, the array will be divided into N equal arrays along axis. If such a split is not possible, an error is raised. If indices_or_sections is a 1-D array of sorted integers, the entries indicate where along axis the array is split. For example, [2, 3] would, for axis=0, result in ary[:2] ary[2:3] ary[3:] If an index exceeds the dimension of the array along axis, an empty sub-array is returned correspondingly. axis : int, optional The axis along which to split, default is 0.
Returns:	sub-arrays : list of ndarrays A list of sub-arrays.
Raises:	ValueError If indices_or_sections is given as an integer, but a split does not result in equal division.

See also

array_split

Split an array into multiple sub-arrays of equal or near-equal size. Does not raise an exception if an equal division cannot be made.

hsplit

Split array into multiple sub-arrays horizontally (column-wise).

vsplit

Split array into multiple sub-arrays vertically (row wise).

dsplit

Split array into multiple sub-arrays along the 3rd axis (depth).

concatenate

Join a sequence of arrays along an existing axis.

stack

Join a sequence of arrays along a new axis.

hstack

Stack arrays in sequence horizontally (column wise).

vstack

Stack arrays in sequence vertically (row wise).

dstack

Stack arrays in sequence depth wise (along third dimension).

Examples

>>> x = np.arange(9.0) >>> np.split(x, 3) [array([ 0., 1., 2.]), array([ 3., 4., 5.]), array([ 6., 7., 8.])] 

>>> x = np.arange(8.0) >>> np.split(x, [3, 5, 6, 10]) [array([ 0., 1., 2.]),  array([ 3., 4.]),  array([ 5.]),  array([ 6., 7.]),  array([], dtype=float64)]