Ignore certain packages and their dependencies with pip freeze

Question

Title basically says it all. How can I tell pip freeze to ignore certain packages, like pylint and pep8, and their dependencies?

Answer 1

on windows with powershell:

 $exclude = 'pylint', 'pep8'  

 pip freeze |  
             Where-Object { $exclude -notcontains $_ } |  
             ForEach-Object { pip install --upgrade $_ }