Python Pandas - 计算到目前为止在每一行的列中找到的字符串

Question

I am doing some analysis and visuals on past NHL seasons and I'm having difficulty in creating some additional data/features in my DataFrame.

This is a simplified version of the dataframe where each row represents one game.

game_id h_abbr a_abbr 
0001    WSH    TOR 
0002    ANA    TOR 
0003    TOR    MIN 

How can I count how many games each team has played so far (including the game in question) so the new column would look like something like this?

game_id h_abbr a_abbr ht_game_no at_game_no
0001    WSH    TOR    1          1
0002    ANA    TOR    1          2
0003    TOR    MIN    3          1

After a lot of searching and trying I have only found a way to count how many home OR away games the team has played, but I am interested in the total games played.

df['Nth_away_game'] = df.groupby('a_abbr').cumcount() + 1

Answer 1

Idea is reshape values by DataFrame.stack , then use GroupBy.cumcount , check columns names by DataFrame.add_suffix and last DataFrame.join to original:

s = df[['h_abbr','a_abbr']].stack()
df = df.join(s.groupby(s).cumcount().add(1).unstack().add_suffix('_no'))
print (df)
   game_id h_abbr a_abbr  h_abbr_no  a_abbr_no
0        1    WSH    TOR          1          1
1        2    ANA    TOR          1          2
2        3    TOR    MIN          3          1