[Python-ideas] slice[] to get more complex slices

For basic slices, the normal "slice(start, stop, step)" syntax works well. But it becomes much more verbose to create more complicated slices that you want to re-use for multiple multidimensional data structures, like numpy, pandas, xarray, etc.

One idea I had was to allow creating slices by using indexing on the slice class. So for example:

x = slice[5:1:-1, 10:20:2, 5:end]

Would be equivalent to:

x = (slice(5, 1, -1), slice(10, 20, 2), slice(5, None))

Note that this wouldn't be done on a slice instance, it would be done on the slice class. The basic idea is that it would simply return whatever is given to __getitem__.