Added testing for pylib

[JJtan2002]

Added test cases for pylib. Added type safety by throwing errors for invalid argument types for binary operators in pylib.

[coveralls]

Pull Request Test Coverage Report for Build 8509705972

Details

• 45 of 65 (69.23%) changed or added relevant lines in 1 file are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage increased (+0.1%) to 81.567%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/stdlib/pylib.ts	45	65	69.23%
<!--	Total:	45	65	69.23%	-->

Totals
Change from base Build 8509696118:	0.1%
Covered Lines:	10691
Relevant Lines:	12722

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💛 - Coveralls

[sayomaki]

Another quick nitpick about the code changes, is there any reason why we are not using strict equality when checking the types?

[JJtan2002]

Another quick nitpick about the code changes, is there any reason why we are not using strict equality when checking the types?

There isn't actually, we'll do a quick change. Thank you for all the help!