On each iteration of your loop the dictionary over writes the same two keys. Would it be preferable to use a list instead or on each loop the key names will need changing to something unique to the dictionary each time.
If you want the two keys values to be a list, first asign each of them as a list outside of the loop then inside the loop append to the list of each key.
If you want the two keys values to be a list, first asign each of them as a list outside of the loop then inside the loop append to the list of each key.