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- Astropy v1.1.1 »
- N-dimensional datasets (`astropy.nddata`) »
- Mixins for added functionality »
- Slicing mixin

# Slicing mixin

The slicing mixin adds the ability to index an `NDData` object in a manner similar to a numpy array. Slicing returns a new `NDData` object with the shape indicated by the slice.

The first step in creating an `NDData`-based object with slicing is to create a new class:

    >>> from astropy.nddata import NDData, NDSlicingMixin
    >>> class MyNDDataWithSlicing(NDSlicingMixin, NDData): pass

Then, initialize the new object the same way you would initialize a plain `NDData` object:

    >>> sliceable_ndd = MyNDDataWithSlicing([1, 2, 3, 4])
    >>> sliceable_ndd[1:3]
    MyNDDataWithSlicing([2, 3])

One important note: the order you list the mixins and `NDData` matters; the base class, `NDData` should be on the far right.