With this maze structure:

house = {
    "living": {
        "exits": {"north": "kitchen", "outside": "garden", "upstairs": "bedroom"},
        "people": ["James"],
        "capacity": 2,
    "kitchen": {"exits": {"south": "living"}, "people": [], "capacity": 1},
    "garden": {"exits": {"inside": "living"}, "people": ["Sue"], "capacity": 3},
    "bedroom": {
        "exits": {"downstairs": "living", "jump": "garden"},
        "people": [],
        "capacity": 1,

We can get a simpler dictionary with just capacities like this:

{name: room["capacity"] for name, room in house.items()}
{'living': 2, 'kitchen': 1, 'garden': 3, 'bedroom': 1}

To get the current number of occupants, we can use a similar dictionary comprehension. Remember that we can filter (only keep certain rooms) by adding an if clause:

{name: len(room["people"]) for name, room in house.items() if len(room["people"]) > 0}
{'living': 1, 'garden': 1}