challenges_done = [('mike', 10), ('julian', 7), ('bob', 5), ('mike', 11), ('julian', 8), ('bob', 6)] challenges = defaultdict(list) for name, challenge in challenges_done: challenges[name].append(challenge) challenges
challenges_done = [('mike', 10), ('julian', 7), ('bob', 5), ('mike', 11), ('julian', 8), ('bob', 6)] challenges = defaultdict(list) for name, challenge in challenges_done: challenges[name].append(challenge) challenges