Slice objects are used to represent slices when extended slice
syntax is used. This is a slice using two colons, or multiple slices
or ellipses separated by commas, e.g.,
a[..., i:j]. They are also created by the built-in slice
Special read-only attributes:
- start is the lower bound
- stop is the upper bound
- step is the step value
Each is of the above is None if omitted.
These attributes can have any type.
Slice objects support one method:
This method takes a single integer argument length and computes information about the extended slice that the slice object would describe if applied to a sequence of length items. It returns a tuple of three integers; respectively these are the start and stop indices and the step or stride length of the slice. Missing or out-of-bounds indices are handled in a manner consistent with regular slices. New in version 2.3.