Thanks for the suggestion though just want to clarify, I am also one of the maintainers of parso :-) (and also the ast module in the standard library)

Extra clarification: I'm well aware the concerns about tokens vs CST vs AST, that is why I decided to write down a library that does refactors on small code fragments rather than just unparse()ing everything. CST is definitely more sound in terms of preserving these details but dealing with it much more complicated than the regular AST. Refactor's README these also mentions other libraries for complex refactors: parso, LibCST, FixIT