Make slice deletion consistent with standard lists, fixes #12

[wetneb]

This reimplements slice deletion to make it consistent with standard lists. Existing test cases have been adapted to reflect this.

See #12.

[johnsyweb]

Thanks for this PR, @wetneb. The tests look good. I'd like to take some time to review the __delitem__() implementation, as that method is getting quite complex now. I'll try to come back to you this week.

[wetneb]

Yeah, I wish I could have come up with a simpler implementation. Feel free to suggest another version if one comes to mind.

[johnsyweb]

@wetneb How does 3be2d80 look?

[wetneb]

It is definitely more readable, but your implementation has higher asymptotic complexity: O(n m) where n is the number of items in the list and m the number of indices to delete, while mine is O(n + m).

If having complexity O(n m) is not a problem for you I would rewrite your version to use comprehensions as it would probably speed things up a bit.

[johnsyweb]

@wetneb Thanks for the analysis. I think 08431bb is better.

[wetneb]

Awesome! It is much more readable like that.

[johnsyweb]

Great! Thanks for your contribution!

[wetneb]

@johnsyweb if you get a chance to release this, it would be useful as it would enable django-haystack/django-haystack#1682 to move forward.

[johnsyweb]

0.8 is now available from https://pypi.org/project/sparse-list/ and https://github.com/johnsyweb/python_sparse_list/releases .

[wetneb]

@johnsyweb thanks a lot! Interestingly it looks like it is not possible to install it for Python 2.7, probably because only a "wheel" distribution was uploaded to PyPI and not a .tar.gz. Since django-haystack is compatible with Python 2.7 it would be useful to make it available for this version of Python as well.

[johnsyweb]

Hmmm...

% python3 -m twine upload dist/*                              

Uploading distributions to https://upload.pypi.org/legacy/
Uploading sparse_list-0.8-py3-none-any.whl
100%|████████████████████████████████████████████████| 11.8k/11.8k [00:03<00:00, 3.33kB/s]
Uploading sparse_list-0.8.tar.gz
100%|████████████████████████████████████████████████| 10.7k/10.7k [00:00<00:00, 27.5kB/s]
NOTE: Try --verbose to see response content.
HTTPError: 403 Client Error: The credential associated with user 'johnsyweb' isn't allowed to upload to project 'sparse-list'. See https://pypi.org/help/#project-name for more information. for url: https://upload.pypi.org/legacy/

Will have another try tonight.

[johnsyweb]

Basic auth works (previously I was using an API key) but you'll need pip install sparse-list==0.8.1.

% python3 -m twine upload dist/*         
Uploading distributions to https://upload.pypi.org/legacy/
Uploading sparse_list-0.8.1-py3-none-any.whl
100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 11.8k/11.8k [00:02<00:00, 5.57kB/s]
Uploading sparse_list-0.8.1.tar.gz
100%|█████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████████| 10.7k/10.7k [00:01<00:00, 7.97kB/s]

[di]

@johnsyweb Can you file an issue at https://github.com/pypa/warehouse/issues with as much detail as possible? If you could attach the original 0.8.0 distributions as well that'd be helpful.

[woodruffw]

Following up here: my current operating theory is that this is caused by API tokens using the non-normalized name, which specifically causes problems for projects with underscores in their names (e.g., sparse_list becomes sparse-list). Normalization isn't reversible, so Project.name for existing uploads becomes the normalized form and our comparison ends up failing.

I'll be confirming this and making the relevant fix(es) in a bit.