numpy.lib.array_utils.normalize_axis_index#
- lib.array_utils.normalize_axis_index(axis, ndim, msg_prefix=None)#
Normalizes an axis index, axis, such that is a valid positive index into the shape of array with
ndim
dimensions. Raises an AxisError with an appropriate message if this is not possible.Used internally by all axis-checking logic.
New in version 1.13.0.
- Parameters:
- axisint
The un-normalized index of the axis. Can be negative
- ndimint
The number of dimensions of the array that axis should be normalized against
- msg_prefixstr
A prefix to put before the message, typically the name of the argument
- Returns:
- normalized_axisint
The normalized axis index, such that 0 <= normalized_axis < ndim
- Raises:
- AxisError
If the axis index is invalid, when -ndim <= axis < ndim is false.
Examples
>>> from numpy.lib.array_utils import normalize_axis_index >>> normalize_axis_index(0, ndim=3) 0 >>> normalize_axis_index(1, ndim=3) 1 >>> normalize_axis_index(-1, ndim=3) 2
>>> normalize_axis_index(3, ndim=3) Traceback (most recent call last): ... numpy.exceptions.AxisError: axis 3 is out of bounds for array ... >>> normalize_axis_index(-4, ndim=3, msg_prefix='axes_arg') Traceback (most recent call last): ... numpy.exceptions.AxisError: axes_arg: axis -4 is out of bounds ...