Class ndindex

numpy/lib/_index_tricks_impl.py:641–709

An N-dimensional iterator object to index arrays. Given the shape of an array, an `ndindex` instance iterates over the N-dimensional index of the array. At each iteration a tuple of indices is returned, the last dimension is iterated over first. Parameters ---------- s

@set_module('numpy')
class ndindex:
    """
    An N-dimensional iterator object to index arrays.

    Given the shape of an array, an `ndindex` instance iterates over
    the N-dimensional index of the array. At each iteration a tuple
    of indices is returned, the last dimension is iterated over first.

    Parameters
    ----------
    shape : ints, or a single tuple of ints
        The size of each dimension of the array can be passed as
        individual parameters or as the elements of a tuple.

    See Also
    --------
    ndenumerate, flatiter

    Examples
    --------
    >>> import numpy as np

    Dimensions as individual arguments

    >>> for index in np.ndindex(3, 2, 1):
    ...     print(index)
    (0, 0, 0)
    (0, 1, 0)
    (1, 0, 0)
    (1, 1, 0)
    (2, 0, 0)
    (2, 1, 0)

    Same dimensions - but in a tuple ``(3, 2, 1)``

    >>> for index in np.ndindex((3, 2, 1)):
    ...     print(index)
    (0, 0, 0)
    (0, 1, 0)
    (1, 0, 0)
    (1, 1, 0)
    (2, 0, 0)
    (2, 1, 0)

    """

    def __init__(self, *shape):
        if len(shape) == 1 and isinstance(shape[0], tuple):
            shape = shape[0]
        if min(shape, default=0) < 0:
            raise ValueError("negative dimensions are not allowed")
        self._iter = product(*map(range, shape))

    def __iter__(self):
        return self

    def __next__(self):
        """