dask.array.append — Dask documentation (original) (raw)

dask.array.append¶

dask.array.append(arr, values, axis=None)[source]¶

Append values to the end of an array.

This docstring was copied from numpy.append.

Some inconsistencies with the Dask version may exist.

Parameters

arrarray_like

Values are appended to a copy of this array.

valuesarray_like

These values are appended to a copy of arr. It must be of the correct shape (the same shape as arr, excluding axis). Ifaxis is not specified, values can be any shape and will be flattened before use.

axisint, optional

The axis along which values are appended. If axis is not given, both arr and values are flattened before use.

Returns

appendndarray

A copy of arr with values appended to axis. Note thatappend does not occur in-place: a new array is allocated and filled. If axis is None, out is a flattened array.

See also

insert

Insert elements into an array.

delete

Delete elements from an array.

Examples

import numpy as np
np.append([1, 2, 3], [[4, 5, 6], [7, 8, 9]])
array([1, 2, 3, ..., 7, 8, 9])

When axis is specified, values must have the correct shape.

np.append([[1, 2, 3], [4, 5, 6]], [[7, 8, 9]], axis=0)
array([[1, 2, 3], [4, 5, 6], [7, 8, 9]])

np.append([[1, 2, 3], [4, 5, 6]], [7, 8, 9], axis=0)
Traceback (most recent call last): ... ValueError: all the input arrays must have same number of dimensions, but the array at index 0 has 2 dimension(s) and the array at index 1 has 1 dimension(s)

a = np.array([1, 2], dtype=int)
c = np.append(a, [])
c
array([1., 2.]) c.dtype
float64

Default dtype for empty ndarrays is float64 thus making the output of dtypefloat64 when appended with dtype int64