add_match.py

#!/usr/bin/python

import sqlite3
import sys
import elo
import datetime

DEFAULT_RATING = 1500

def get_rating(con, player):
    cur = con.cursor()
    rating = cur.execute("""
        SELECT rating 
          FROM player
         WHERE short_name = '{0}'""".format(player)).fetchone()

    return float(rating[0])

def log_match_info(player_a, score_a, player_b, score_b, rating_a, rating_b, new_rating_a, new_rating_b):
    print "{0} won the Match! {1} - {2}".format(player_a if score_a > score_b else player_b, score_a, score_b)
    print 
    print "{0} {1} {2:.2f} points. His new rating is {3:.2f}".format(player_a, 'won' if new_rating_a > rating_a else 'lost', abs(new_rating_a-rating_a), new_rating_a)
    print
    print "{0} {1} {2:.2f} points. His new rating is {3:.2f}".format(player_b, 'won' if new_rating_b > rating_b else 'lost', abs(new_rating_b-rating_b), new_rating_b) 

def add_match(player_a, score_a, player_b, score_b, verbose):
    con = sqlite3.connect('pingpong.db') 
    cur = con.cursor() 

    rating_a = get_rating(con, player_a)
    rating_b = get_rating(con, player_b)

    if not rating_a:
        print "Error: Rating for player {0} was not found".format(player_a)
        return

    if not rating_b:
        print "Error: Rating for player {0} was not found".format(player_b)
        return
    
    new_rating_a, new_rating_b = elo.compute_new_ratings(score_a, rating_a, score_b, rating_b)

    query = """
         INSERT INTO match 
             (player_a, player_b, score_a, score_b, elo_won_a, elo_won_b, date) 
         VALUES ('{0}','{1}','{2}','{3}','{4}','{5}', '{6}')
            """.format(
                player_a, player_b, 
                score_a, score_b, 
                new_rating_a - rating_a,
                new_rating_b - rating_b,
                str(datetime.datetime.now())
                ) 
    cur.execute(query) 

    query = """
        UPDATE player
           SET rating = {0}
         WHERE short_name = '{1}'"""

    cur.execute(query.format(new_rating_a, player_a))
    cur.execute(query.format(new_rating_b, player_b))

    if verbose:
        log_match_info(player_a, score_a, player_b, score_b, rating_a, rating_b, new_rating_a, new_rating_b)

    con.commit() 
    cur.close()
    con.close()

if __name__ == "__main__":
    if len(sys.argv) != 5:
        print "Incorrect number of parameters."
        print "  Usage: ./add_match player_a score_a player_b score_b"
    else:
        add_match(sys.argv[1], int(sys.argv[2]), sys.argv[3], int(sys.argv[4]), True)