I guess the link to the Python 2 version of the library was only by accident. If some new functionality in Nim should be modeled after Python, refer to the documentation for Python 3.
For most older libraries, there shouldn't be a big difference, but for newer libraries there may be, and even older modules might be improved in Python 3. So, here's the link: [https://docs.python.org/3/library/os.html#os.walk](https://docs.python.org/3/library/os.html#os.walk) . Note that I used `/3/` in the URL, so you'll get the documentation for the most recent Python 3 version. If you select a specific version (e. g. 3.8) from the drop-down menu at the top of the page, you'll get the documenation as of this version.
