Calling dict.keys() is unnecessary. The two are functionally equivalent
on modern Pythons.
Inspired by Lennart Regebro's talk "Prehistoric Patterns in Python" from
PyCon 2017.
https://www.youtube.com/watch?v=V5-JH23Vk0I
It is possible that a key in a MultiValueDict has multiple values, lists
are represented this way. When accessing a key in a MultiValueDict
it only returns the last element of that key. This becomes a problem
when parsing an html dict with a list inside of it.
To fix this problem we have to get and set the value using .getlist()
and .setlist().