Produce a league table from a list of match results.

league.py

"""
Module that processes a list of results, and produces a sorted league table.

The list of results is a pandas data frame with format
   "Home"    "Home Score"   "Away"  "Away Score" 
0  "Chelsea" 4              "Man U" 2
1   ...      ...            ...     ...

Result is a Data frame representing the league table

        Played Wins Losses Draws For Against Points Difference
Chelsea 1      1    0      0     4   2       3      2 
Man U   1      0    1      0     2   4       0     -2


"""

import pandas as pd

def matches_played(team, results):
    home = results[results.Home == team]
    away = results[results.Away == team]
    return pd.concat([home, away])

def get_wins(team, results):
    home_win = results[(results.Home == team)
                       & (results["Home Score"] > results["Away Score"])]
    away_win = results[(results.Away == team)
                       & (results["Home Score"] < results["Away Score"])]
    return pd.concat([home_win, away_win])

def get_draws(team, results):
    home_draw = results[(results.Home == team)
                        & (results["Home Score"] == results["Away Score"])]
    away_draw = results[(results.Away == team)
                        & (results["Home Score"] == results["Away Score"])]
    return pd.concat([home_draw, away_draw])

def get_losses(team, results):
    home_loss = results[(results.Home == team)
                        & (results["Home Score"] < results["Away Score"])]
    away_loss = results[(results.Away == team)
                        & (results["Home Score"] > results["Away Score"])]
    return pd.concat([home_loss, away_loss])

def goals_for(team, results):
    home_goals = results[results.Home == team]["Home Score"].sum()
    away_goals = results[results.Away == team]["Away Score"].sum()
    return home_goals + away_goals

def goals_against(team, results):
    home_goals = results[results.Home == team]["Away Score"].sum()
    away_goals = results[results.Away == team]["Home Score"].sum()
    return home_goals + away_goals

def make_league_table(teams, results, points_per_win=3, points_per_draw=1):
    league_table = pd.DataFrame(
        {
            "Played": [len(matches_played(team, results)) for team in teams],
            "Wins": [len(get_wins(team, results)) for team in teams],
            "Losses": [len(get_losses(team, results)) for team in teams],
            "Draws": [len(get_draws(team, results)) for team in teams],
            "For": [goals_for(team, results) for team in teams],
            "Against": [goals_against(team, results) for team in teams]
        },
        index=teams,
        columns=["Played", "Wins", "Losses", "Draws", "For", "Against"]
    )
    league_table['Points'] = (league_table.Wins * points_per_win 
                            + league_table.Draws * points_per_draw)
    league_table['Difference'] = league_table.For - league_table.Against
    return league_table.sort_values(by=["Points", "Difference"], 
                                    ascending=False)


def main():
    teams = ["Meads", "Crawley", "Cuckfield"]

    data = [
            ["Meads", 1, "Crawley", 0],
            ["Meads", 2, "Cuckfield", 2],
            ["Crawley", 3, "Cuckfield", 2],
            ["Cuckfield", 0, "Meads", 0],
            ["Crawley", 0, "Meads", 1],
            ["Cuckfield", 3, "Crawley", 2],
           ]

    results = pd.DataFrame(
        data,
        columns=[
            "Home",
            "Home Score",
            "Away",
            "Away Score"])

    print(make_league_table(teams, results))

if __name__ == "__main__":
    main()