I would love to be able to search all code for a string and then either (1) sort the resulting repositories by stars/forks; or (2) limit the results to repositories with >X stars/forks. When learning a new framework or library I like to find popular projects that use it and read the code to get a sense of conventions, architecture, etc. For instance, it'd be fantastic to find all repositories with over 20 stars containing a *.py file with "import flask" or "from flask" in them.