Which database is best for stuff like this?
And works with Python.
And works with Python.
Once you have a lot of data, it really depends on your specific situation. If you don't have any preferences, you can try something new - MongoDB is interesting.
Out of all the nosql options, why pick the one with the most broken default configuration? People complain that MongoDB is has a bad rep when used for things its not meant to, and then its constantly offered as solution.