Next Code python bee scoring

scoring.py

'''
Expects an "answer.py" in the same directory containing the answer

Example usage:
register team: "add=melonpan"
correct answer: "team=melonpan stars=3"
challenge solution: "team=notmelonpan stars=3 challenge"
wrong answer: "team=melonpan wrong"
'''

teams = {}

def score(p):
    with open('answer.py') as f:
        code = f.read().split('\n')[:-1]
    avg = sum([len(l) for l in code])/len(code)
    return int(max(100, (1+int(p['stars']))*(1000*0.7**(len(code)-1) - 4*avg)))

prev = 0
i = ''
while True:
    i = input('> ').split()
    params = {}
    for arg in i:
        if '=' in arg:
            k,v = arg.split('=')
            params[k] = v
        else:
            params[arg] = 1

    if 'add' in params:
        teams[params['add']] = 0
        print("Team {} registered!".format(params['add']))
        continue

    if 'challenge' in params:
        if score(params) <= prev:
            print("This solution is worse! 500 point penalty.")
            teams[params['team']] -= 500
            print("Scores: " + str(teams))
            continue

    if 'wrong' in params:
        print("500 point penalty.")
        teams[params['team']] -= 500
    else:
        s = score(params)
        teams[params['team']] += s
        prev = s
        print("Awarding {} points".format(s))


    print("Scores: " + str(teams))