How to map to a dictionary
===

So I've got a list that looks like so:

    [['hostile', 'angry'], ['elated', 'happy'], ['elated', 'grateful'], ['depressed', 'sad']]

Generated by this:

    c.execute("""SELECT category, wordlist from wordtest order by category""")
                    categoryfile = c.fetchall()
                    categoryfile = [list(x) for x in categoryfile]

I want all of the values of category to be merged into a single key, and then all of the words from wordlist that would be paired with that category merged into one list. Is that possible?

So ultimately, with that list, you'd instead see 

> ['elated', 'happy'], ['elated', 'grateful']

turn into:

    {'elated': ['happy', 'grateful']}