Warnings raised with Python 3.10

[EmilyBourne]

Python 3.10 raises the following warnings:

/home/emily/Code/loki/scripts/loki_transform.py:166: SyntaxWarning: "is" with a literal. Did you mean "=="?
  directive = None if directive is 'none' else directive.lower()
/home/emily/Code/loki/scripts/loki_transform.py:450: SyntaxWarning: "is" with a literal. Did you mean "=="?
  directive = None if directive is 'none' else directive.lower()

As described here equal literals are not guaranteed to be the same object so this if evaluation may occasionally give wrong results on some systems

[EmilyBourne]

I have not tested but as per Python's changelog this warning should appear in all active Python versions (3.8 onwards, 3.7 recently reached end of life)

[reuterbal]

Thanks for pointing this out. This is a bug in loki_transform.py that I had indeed fixed on a branch but apparently never contributed back.