Looks like it's recently been updated but no big announcement that it's Python 3 ready: https://github.com/python-mechanize/mechanize

I've also seen these alternatives:

- https://robobrowser.readthedocs.io/en/latest/

- https://github.com/MechanicalSoup/MechanicalSoup

MechanicalSoup seems well updated but the last time I tried these libraries, they were either buggy (and/or I was ignorant) and I just couldn't get things to work as I was used to in Ruby and Mechanize.