mindspore.dataset.transforms.c_transforms.Slice

class mindspore.dataset.transforms.c_transforms.Slice(*slices)[source]

Slice operation to extract a tensor out using the given n slices.

The functionality of Slice is similar to NumPy’s indexing feature (Currently only rank-1 tensors are supported).

Parameters

slices (Union[int, list[int], slice, None, Ellipsis]) –

Maximum n number of arguments to slice a tensor of rank n . One object in slices can be one of:

  1. int: Slice this index only along the first dimension. Negative index is supported.

  2. list(int): Slice these indices along the first dimension. Negative indices are supported.

  3. slice: Slice the generated indices from the slice object along the first dimension. Similar to start:stop:step.

  4. None: Slice the whole dimension. Similar to [:] in Python indexing.

  5. Ellipsis: Slice the whole dimension, same result with None.

Examples

>>> # Data before
>>> # |   col   |
>>> # +---------+
>>> # | [1,2,3] |
>>> # +---------|
>>> data = [[1, 2, 3]]
>>> numpy_slices_dataset = ds.NumpySlicesDataset(data, ["col"])
>>> # slice indices 1 and 2 only
>>> numpy_slices_dataset = numpy_slices_dataset.map(operations=c_transforms.Slice(slice(1,3)))
>>> # Data after
>>> # |   col   |
>>> # +---------+
>>> # |  [2,3]  |
>>> # +---------|