Run 2to3 with multiple threads

Automated Python 2 to 3 code conversion.
More information: <https://docs.python.org/3/library/2to3.html>.
Trick copyright: tl;dr; <https://github.com/tldr-pages/tldr>

2to3 --processes={{4}} --output-dir={{path/to/python3_directory}} --write --nobackups --no-diff {{path/to/python2_directory}}

click the source code to copy install 2to3 on any operating system with command-not-found.com