larray.Array.reindex

Array.reindex(axes_to_reindex=None, new_axis=None, fill_value=nan, inplace=False, **kwargs) → Array[source]

Reorder and/or add new labels in axes.

Place NaN or given fill_value in locations having no value previously.

Parameters

axes_to_reindexaxis ref or dict {axis ref: axis} or list of (axis ref, axis) or sequence of Axis: Axis(es) to reindex. If a single axis reference is given, the new_axis argument must be provided. If string, Group or Axis object, the corresponding axis is reindexed if found among existing, otherwise a new axis is added. If a list of Axis or an AxisCollection is given, existing axes are reindexed while missing ones are added.
new_axisint, str, list/tuple/array of str, Group or Axis, optional: List of new labels or new axis if axes_to_reindex contains a single axis reference.
fill_valuescalar or Array, optional: Value used to fill cells corresponding to label combinations which were not present before reindexing. Defaults to NaN.
inplacebool, optional: Whether to modify the original object or return a new array and leave the original intact. Defaults to False.
**kwargsAxis: New axis for each axis to reindex given as a keyword argument.

Returns

Array: Array with reindexed axes.

Notes

When introducing NaNs into an array containing integers via reindex, all data will be promoted to float in order to store the NaNs.

Examples

>>> arr = ndtest((2, 2))
>>> arr
a\b  b0  b1
 a0   0   1
 a1   2   3
>>> arr2 = ndtest('a=a1,a2;c=c0;b=b2..b0')
>>> arr2
 a  c\b  b2  b1  b0
a1   c0   0   1   2
a2   c0   3   4   5

Reindex an axis by passing labels (list or string)

>>> arr.reindex('b', ['b1', 'b2', 'b0'])
a\b   b1   b2   b0
 a0  1.0  nan  0.0
 a1  3.0  nan  2.0
>>> arr.reindex('b', 'b0..b2', fill_value=-1)
a\b  b0  b1  b2
 a0   0   1  -1
 a1   2   3  -1
>>> arr.reindex(b='b=b0..b2', fill_value=-1)
a\b  b0  b1  b2
 a0   0   1  -1
 a1   2   3  -1

Reindex using an axis from another array

>>> arr.reindex('b', arr2.b, fill_value=-1)
a\b  b2  b1  b0
 a0  -1   1   0
 a1  -1   3   2

Reindex using a subset of an axis

>>> arr.reindex('b', arr2.b['b1':], fill_value=-1)
a\b  b1  b0
 a0   1   0
 a1   3   2

Reindex by passing an axis or a group

>>> arr.reindex('b=b2..b0', fill_value=-1)
a\b  b2  b1  b0
 a0  -1   1   0
 a1  -1   3   2
>>> arr.reindex(arr2.b, fill_value=-1)
a\b  b2  b1  b0
 a0  -1   1   0
 a1  -1   3   2
>>> arr.reindex(arr2.b['b1':], fill_value=-1)
a\b  b1  b0
 a0   1   0
 a1   3   2

Reindex several axes

>>> arr.reindex({'a': arr2.a, 'b': arr2.b}, fill_value=-1)
a\b  b2  b1  b0
 a1  -1   3   2
 a2  -1  -1  -1
>>> arr.reindex({'a': arr2.a, 'b': arr2.b['b1':]}, fill_value=-1)
a\b  b1  b0
 a1   3   2
 a2  -1  -1
>>> arr.reindex(a=arr2.a, b=arr2.b, fill_value=-1)
a\b  b2  b1  b0
 a1  -1   3   2
 a2  -1  -1  -1

Reindex by passing a collection of axes

>>> arr.reindex(arr2.axes, fill_value=-1)
 a  b\c  c0
a1   b2  -1
a1   b1   3
a1   b0   2
a2   b2  -1
a2   b1  -1
a2   b0  -1
>>> arr2.reindex(arr.axes, fill_value=-1)
 a  c\b  b0  b1
a0   c0  -1  -1
a1   c0   2   1