I want to generate the list of packages install in Python 3, the list of all packages in Python 2.7 and find all entries in the 2.7 list not in the Python 3 list.
Generating the list is easy:
pip freeze | grep "wheel"
pip freeze | grep -n pip3.4 freeze
...is not a file or directory
you can use also comm command as below
comm -12 <(pip freeze) <(pip3.4 freeze)
to search for intersections;
grep -f <(pip freeze) <(pip3.4 freeze)