Implement DataSourceList.sample_spatial_and_temporal_locations_for_examples()

[JackKelly]

Pull Request

Description

This PR is part of #213.

Specifically, this PR is about implementing compute_and_save_positions_of_each_example_of_each_split() and its helper functions.

This PR implements:

• Removed a few unused imports.
• A new class, DataSourceList, for working with lists of DataSources 🙂
• NowcastingDataModule._get_t0_datetimes() is moved into DataSourceList.get_t0_datetimes_across_all_data_sources().
• Implement DataSourceList.sample_spatial_and_temporal_locations_for_examples()
• Rename DataSource.get_locations_for_batch() to DataSource.get_locations() (this touches a lot of files but is a simple change!)
• Use a namedtuple as the return type from split_data (to make sure we don't confuse train, test, and validation!)
• Removed some NotImplemented functions from child classes.
• Test DataSourceList.sample_spatial_and_temporal_locations_for_examples()

How Has This Been Tested?

Tests have been updated and all pass.

• No
• Yes

Checklist:

• My code follows OCF's coding style guidelines
• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• I have added tests that prove my fix is effective or that my feature works
• I have checked my code and corrected any misspellings

[JackKelly]

Hi @jacobbieker I think this is pretty much ready for review now!

It looks like a lot of changes but the core changes are pretty simple!

I haven't yet written a test for DataSourceList.sample_position_of_every_example_of_every_split(). I will do so in the next few hours. But, apart from that, I think this PR is ready for review. Thank you!

[jacobbieker]

Looks good! I like how its done!