Slice with step
Input
SliceableList([0, 1, 2, 3, 4, 5])[::2]
Output
[0, 2, 4]
A step of 2 selects every second item starting at index 0.
Full lesson preview
Support Slicing in __getitem__ for a Sequence
Extend indexing to accept slice objects so your sequence supports ranges, steps, and omitted bounds.
Python practice16 minMagic Methods & Operator OverloadingIntermediateLast updated April 11, 2026
Problem statement
Enhance a sequence wrapper, SliceableList, so that accessing it with a slice (e.g., obj[1:4], obj[:], obj[::2]) returns a new list containing the selected elements. The class should also continue to support integer indexing.
Requirements:
- If key is an int, return the corresponding element (support negative indices as Python lists do).
- If key is a slice, return a new list corresponding to self._items[key] (preserve Python slicing semantics for start, stop, step, negative steps, and out-of-range bounds).
- For other key types, raise TypeError.
Returning a list for slices keeps behavior simple and predictable for callers and tests.
Task
Implement __getitem__ that accepts both integer indices and slice objects; slice results should return a standard Python list.
Examples
Input format
Expressions like SliceableList([...])[start:stop:step] or SliceableList([...])[index].
Output format
The returned element (for integer index) or a list (for slice). Tests compare str(returned_value).
Constraints
- Must support both int and slice keys in __getitem__.
- For slices, return a Python list containing the selected items.
- For unsupported key types, raise TypeError.
Samples
Sample 1
Input
SliceableList(["a", "b", "c", "d"])[1:3]
Output
['b', 'c']
Slicing from 1 (inclusive) to 3 (exclusive) returns ['b', 'c'].