Build and read

person = {"name": "Ada", "city": "Nairobi", "score": 98}
print(person["name"])
print(person.get("team", "none"))
print("city" in person)
print(list(person.keys()))
print(list(person.values()))

Missing person["team"] raises KeyError. .get returns the default instead.

Set and delete

person = {"name": "Ada", "score": 91}
person["score"] = 98
person["city"] = "Nairobi"
del person["score"]
print(person)

Iterate

scores = {"Ada": 98, "Alan": 91, "Grace": 95}
for name, score in scores.items():
    print(f"{name}: {score}")
print(sum(scores.values()))

Nested

team = {
    "Ada": {"city": "Nairobi", "score": 98},
    "Alan": {"city": "Mombasa", "score": 91},
}
print(team["Ada"]["city"])
print(team["Alan"]["score"])

Pitfall

{} is an empty dict, not an empty set. Empty set is set().