Thank you for your feedback. I definitely understand your reasoning and commitment to not introducing breaking changes in externally facing codes. I also agree that this does fall slightly more on the side of aesthetic rather than functional changes. However, this change doesn't seem like it is significantly altering the interface of strtobool; if anything it is making it clearer and less surprising, especially for Python 2/3+ users.

I know, as someone in that category, having learned Python at version 2.5, that it was a bit surprising when I got back an integer from this function rather than the native True and False values. I also want to emphasize that this change is specifically targeting Python 3.6, not 2.7, 3.4, or 3.5. Making this small change in a not-yet-released version should be safe, but, of course, that is my outsider opinion. You absolutely have a valid point if I were asking that we change a released version and it is not something I take lightly.

Lastly, this is the kind of change I would hope I could make easily as a first time contributor to the project because of it being more of an aesthetic one. After all, isn't the whole point of making changes to a project about making it cleaner, modern, and clearer?

Thanks again. I really appreciate the feedback and discussion. P.S. If there is support to introduce this change, I will certainly update the tests and docs as pointed out.