Python resolves this with docstrings but in general, assuming it is not self explanatory while a function exist, is it really necessary to go the whole nine wit

Python resolves this with docstrings but in general, assuming it is not self explanatory while a function exist, is it really necessary to go the whole nine with literate programming instead of just adding a few comments to explain why this exist. Self-documenting code with explanations when necessary is how most codebases already are. At least most good ones.