I have the following .csv file :
Match_idx,Date,Player_1,Player_2,Player_1_wins
0,2020-01-01,p1,p2,1
1,2020-01-02,p2,p3,0
2,2020-01-03,p3,p1,1
3,2020-01-04,p4,p1,1
I want to compute some more columns to obtain the following output .csv file :
Match_idx,Date,Player_1,Player_2,Player_1_wins,Player_1_winrate,Player_2_winrate,Player_1_matches,Player_2_matches,Head_to_head
0,2020-01-01,p1,p2,1,0,0,0,0,0,''
1,2020-01-02,p2,p3,0,0,0,1,0,0,''
2,2020-01-03,p3,p1,1,1,1,1,1,0,''
3,2020-01-04,p4,p1,1,0,1/2,0,2,0,''
4,2020-01-05,p1,p3,0,1/2,2/2,3,2,'0'
5,2020-01-06,p3,p1,1,1/3,3/3,4,3,'11'
The semantic of each column :
Match_idx
,Date
,Player_1
,Player_2
: straightforwardPlayer_1_wins
: didPlayer_1
win the match ? 1 : 0
Those columns will be maintained and I want to add these ones :
-
Player_1_winrate
: number_of_wins_for_player_1_before_this_one / number_of_matches_played_by_player_1_before_this_one -
Player_2_winrate
: same as above for player_2 -
Player_1_matches
: number_of_matches_played_by_player_1_before_this_one -
Player_2_matches
: same as above for player_2 -
Head_to_head
: outcomes of previous matches betweenPlayer_1
andPlayer_2
. Encoded as a string of {'0' and '1'} with '1' ifPlayer_1
won the match, else '0'.
What I have done
I am using pandas library to manipulate this file. The naive approach I've been thinking of is as follow : select each match, lost or won, played by a player, and order by date. After that, for the win ratio feature, apply the two following functions to a match.
def get_matches_won_before_by_player(df: pd.DataFrame, player: str, before: str):
mask_player_won = (
((df['Player_1_wins'] == 1) & (df['Player_1'] == player)) |
((df['Player_1_wins'] == 0) & (df['Player_2'] == player))
)
req = df[(df['Date'] < before) & mask_player_won]
req.sort_values(by='Date', inplace=True)
return req
def get_matches_played_before_by_player(df: pd.DataFrame, player: str, before: str):
mask_player_played = (
(df['Player_1'] == player) |
(df['Player_2'] == player)
)
req = df[(df['Date'] < before) & mask_player_played]
req.sort_values(by='Date', inplace=True)
return req
I could apply that logic to every match but this would involve to run those functions for each match, which is very very ineffective.
What I would like to do
How can I compute my features efficiently using only the last match of each player of a given match ? For example, updating the win rate of each player could be done with the following logic :
- Initialize each column to 0.
- Update win ratio as follow : (M/M+1) + (W/N+1), with
M
the current win ratio,N
the current number of matches played andW
= 1 if player won, else 0.
Any help or idea to organize such a process is much appreciated.
from Efficiently compute temporal features with pandas
No comments:
Post a Comment