Missing commas in tuples results in implicit string concatenation. Probably not what you intended to do.
Implicit string concatenation that resulted from a typo can change the behaviour of the application. Take for example:
is_positive('agreed') evaluates to
False because a typo resulted in the comma being missed from the end of
'affirmative', resulting in
'agreed' being implicitly concatenated to
If our GitHub code review bot spots this issue in your pull request it gives this advice:
Code Review Doctor will run this check by default. No configuration is needed but the check can be turned on/off using check code
avoid-missing-comma in your pyproject.toml file.