The fingerprint matcher

A DNA fingerprint is a set of band sizes in kilobases (kb). You will write three functions that decide which man can be the father of a child.

The idea. Half of the bands of a child come from its mother. The other bands must come from its father. A man can be the father only if he has all of them.

Your tasks.

1. Finish from_father. It gives the set of bands of the child that the mother does not have.
2. Finish can_be_father. It gives True if a man has every band in that set.
3. Finish fathers. It takes a dictionary of names and band sets, and gives the list of names of the men who can be the father.