# How to extract a zero dimensional slice from a one dimensional array in numpy

Is there a way to slice a zero dimensional submatrix from a one dimensional array?

For example, if I have N-dimensional `ndarray`

`arr`

, it `arr[0]`

returns (N-1) -dimensional `ndarray`

.

However, if I have a 1-dimensional `ndarray`

`x`

, it `x[0]`

does not return a 0-dimensional ndarray, but rather a `numpy.int64`

, (if `x`

contains `int64`

s).

Minimal example:

``````def increment(zero_d_array):
zero_d_array[...] = zero_d_array + 1

counter = numpy.array(0)  # a zero-dimensional array containing scalar 0
increment(counter)        # success; counter is now 1

counters = numpy.zeros(3, dtype=int)  # [0, 0, 0]
increment(counter[1])    # fails; counter[1] is a numpy.int64, not a 0-D array
```

```

I understand that the above will work with `increment(counter[1:2])`

, but only because it `increment()`

works with both 0-D and 1-D inputs. Not all features will be that flexible.

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Use ellipsis:

``````increment(counter[1, ...])
```

```
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