elo.py

//Program by: Jarrod Servilla
//June 3rd, 2018

def calc_e(rate_a: int, rate_b: int) -> float:
    return 1 / (1 + 10 ** ( (rate_b - rate_a) / 400) )

def calc_rating(old_rating: int, e: float, is_win: bool) -> int:
    s = 0
    if is_win:
        s = 1
    return int(old_rating + 32 * (s - e))

def import_ratings() -> dict:
    file = open("ratings.txt", "r")
    d = {}
    for line in file:
        if line != '':
            L = line.split(" ")
            d[L[0]] = int(L[1][:4])
    file.close()
    return(d)

def interpret(d: dict, tournament: str) -> dict:
    file = open(tournament, "r")
    for line in file:
        if line != '' :
            L = line.split(" ")
            is_win = False

            if L[2] == 'T\n' or L[2] == 'T':
                is_win = True

            old_a = d.get(L[0], 1700)
            old_b = d.get(L[1], 1700)

            d[L[0]] = calc_rating(old_a, calc_e(old_a, old_b), is_win)
            d[L[1]] = calc_rating(old_b, calc_e(old_b, old_a), not is_win)

    file.close()

    return d

def save_to_file(file_name: str, d: dict):
    file = open(file_name, 'w')
    for (key, value) in d.items():
        file.write(key + ' ' + str(value) + '\n')
    file.close()

def update(tournament: str):
    d = import_ratings()
    d = interpret(d, tournament)

    save_to_file('ratings.txt', d)
    save_to_file(tournament, d)

def record_elos(file_name: str, d: dict):
    file = open(file_name, 'r')
    for line in file:
        if line != '':
            L = line.split(" ")

            if L[0] not in d:
                d[L[0]] = [int(L[1][:4])]
            else:
                d[L[0]].append(int(L[1][:4]))
    file.close()

    file2 = open('graph.txt', 'w')
    for (key, value) in d.items():
        file2.write(key + ' ' + str(value) + '\n')
    file2.close()