A key in code

You will write the key to the phyla as a function, use it on five mystery animals, and count how many of them are chordates.

The idea. Ask about the level first, then the symmetry, then the body cavity, then the notochord. Stop as soon as an answer settles the group.

Your tasks.

1. Finish animal_group. It must return "Porifera", "Coelenterata", "Platyhelminthes", "Aschelminthes", "Chordata" or "non-chordate coelomate".
2. Set groups to the group of each mystery animal, in order.
3. Set chordates to the number of mystery animals that are chordates.