tournament.py

# Simulate a sports tournament

import csv
import sys
import random

# Number of simuulations to run
N = 1000


def main():

    print('')

    # Ensure correct usage
    if len(sys.argv) != 2:
        sys.exit("Usage: python tournament.py FILENAME")

    # Read teams into memory from file
    teams = []
    try:
        file = open(sys.argv[1], 'r')
    except:
        print(f'\033[31mError opening the file "{sys.argv[1]}"\033[m\n')
        sys.exit(1)

    reader = csv.DictReader(file)
    for pos, team in enumerate(reader):
        teams.append(team)  # Append the team into teams list
        teams[pos]['rating'] = int(teams[pos]['rating'])  # Converts rating of a team to int

    # TODO: Simulate N tournaments and keep track of win counts
    counts = {}
    for c in range(N):
        winner = simulate_tournament(teams)
        if winner not in counts:
            counts[winner] = 0
        counts[winner] += 1

    # Print each team's chances of winning, according to simulation
    for team in sorted(counts, key=lambda team: counts[team], reverse=True):
        print(f"{team}: {counts[team] * 100 / N:.1f}% chance of winning")

    print('')


def simulate_game(team1, team2):
    """Simulate a game. Return True if team1 wins, False otherwise."""
    rating1 = team1["rating"]
    rating2 = team2["rating"]
    probability = 1 / (1 + 10 ** ((rating2 - rating1) / 600))
    return random.random() < probability


def simulate_round(teams):
    """Simulate a round. Return a list of winning teams."""
    winners = []

    # Simulate games for all pairs of teams
    for i in range(0, len(teams), 2):
        if simulate_game(teams[i], teams[i + 1]):
            winners.append(teams[i])
        else:
            winners.append(teams[i + 1])

    return winners


def simulate_tournament(teams):
    """Simulate a tournament. Return name of winning team."""
    winners = teams

    # Will simulate rounds until theres only one winner
    while len(winners) > 1:
        winners = simulate_round(winners)

    # Returns the name of that winner
    return winners[0]['team']


if __name__ == "__main__":
    main()