While working on a django project recently, I had to remove all the .pyc files before running syncdb. These are the kinds of commands I want to know well:
find . -name "*.pyc" type -f | xargs rm -f
This finds all files with a name ending in .pyc, and sends these filenames to the rm command. Of course, with any operation like this it is a really good habit to run the find command by itself first, and only run the full command when you are sure you will be removing the correct files.