fix logging

[casperdcl]

Changes

• fix logging usage (fixes Inconsistency in how logging works across CIL #1755)
• upgrade some log.warnings => warnings.warn
• in two files, rename logger => log for consistency & brevity

Testing you performed

TESTS_FORCE_GPU=1 python -m unittest discover ./Wrappers/Python/test

Related issues/links

• Use logging instead of prints #865
• Inconsistency in how logging works across CIL #1755

Checklist

• I have performed a self-review of my code
• I have added docstrings in line with the guidance in the developer guide
• I have updated the relevant documentation
• I have implemented unit tests that cover any new or modified functionality
• CHANGELOG.md has been updated with any functionality change
• Request review from all relevant developers
• Change pull request label to 'Waiting for review'

Contribution Notes

Please read and adhere to the developer guide and local patterns and conventions.

• The content of this Pull Request (the Contribution) is intentionally submitted for inclusion in CIL (the Work) under the terms and conditions of the Apache-2.0 License
• I confirm that the contribution does not violate any intellectual property rights of third parties

[gfardell]

I'm not sure I understand the use case of logging in the unittests. But as this is just updating what was currently implemented it looks good to me.

[lauramurgatroyd]

So we use 'warnings' instead of logging for deprecated code - is this because it means the deprecation message will always be displayed no matter what the logging level is?

[casperdcl]

So we use 'warnings' instead of logging for deprecated code - is this because it means the deprecation message will always be displayed no matter what the logging level is?

Yes and also it will only be displayed once per interpeter session rather than once per function call.