numpy.lib.array_utils.normalize_axis_index#
- lib.array_utils.normalize_axis_index(axis, ndim, msg_prefix=None)#
标准化轴索引 axis ,使其成为具有 ndim 维度的数组形状的有效正索引.如果无法实现,则引发带有相应消息的 AxisError.
由所有轴检查逻辑在内部使用.
- 参数:
- 轴int
轴的未标准化索引.可以为负数
- ndimint
数组的维度数, axis 应该针对该维度数进行标准化
- msg_prefixstr
放在消息前面的前缀,通常是参数的名称
- 返回:
- normalized_axisint
标准化的轴索引,使得 0 <= normalized_axis < ndim
- Raises:
- AxisError
如果轴索引无效,当 -ndim <= axis < ndim 为假时.
示例
>>> import numpy as np >>> 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 ...