NDCollection 2

[DanRyanIrish]

Description

This PR is a continuation of #231. (I messed up the git history and it was easier to open a new PR.) As with #231, this PR introduces a new class for holding a collection of NDCubes/Sequences.

Still To Do

• Get refactor of NDCollection.__init__ working.
• Rename NDCollection.update to something like NDCollection.extend and implement a new NDCollection.update that takes another NDCollection in the same way the dict.update takes another dict.
• Make NDCollection._first_key and NDCollection._cube_types properties.
• Add NDCollection to guide in docs
• Extend tests to NDCollection of NDCubeSequences
• Change aligned_axes default to None
• Changed NDCollection input to (key, value) pairs, like dict.
• Move _sanitize_aligned_axes to ndcollection.py?

[pep8speaks]

Hello @DanRyanIrish! Thanks for updating this PR. We checked the lines you've touched for PEP 8 issues, and found:

• In the file ndcube/tests/helpers.py:

Line 38:37: E721 do not compare types, use 'isinstance()'
Line 46:38: E721 do not compare types, use 'isinstance()'

• In the file ndcube/tests/test_ndcollection.py:

Line 17:101: E501 line too long (102 > 100 characters)
Line 23:101: E501 line too long (102 > 100 characters)

Comment last updated at 2020-03-27 17:52:58 UTC

[DanRyanIrish]

@Cadair, it's done! __setitem__ raises and error. copy works. And pop's docstring is deleted. update now works even more like dict.update and there are guide docs. It's done! Once approved and merged we can release 1.3! I'm done for the week!

[DanRyanIrish]

Drop mic!