numpy select all elements from under array

Question

I have an np.array with 3 dimension. I just want to select all n-th element from the last array.

I know that I can select it like

array[:, :, 0]

But I need to use a function, is there any numpy function to do that ?

Answer 1

The [] operator calls __getitem__ on the object it was used on. In your case, it would be the equivalent of calling

array.__getitem__((slice(None), slice(None), 0))

This is because [:] is an empty slice (i.e. slice(None)), and you are calling the [] operator with 3 value, which is equivalent to calling __getitem__ with a tuple of 3 values.