In a dataframe like this:
...
match team opponent venue
233 3b0345fb Brazil Argentina Home
234 3b2357fb Argentina Brazil Away
427 3b0947fb England Poland Home
...
how can I select one dataframe slice, based on a column value (df[df['team']=='England']
), like this:
...
match team opponent venue
559 4a3eae2f England Poland Home
...
And add inverted rows of that slice to the original dataframe, changing 'Home' with 'Away', ending up with:
...
match team opponent venue
233 3b0345fb Brazil Argentina Home
234 3b2357fb Argentina Brazil Away
559 3b0947fb England Poland Home
560 3b0947fb Poland England Away
...
Note: This slice should contain n rows and produce n inverted rows.
CodePudding user response:
You can use:
df2 = df[df['team'].eq('England')].copy()
df2[['team', 'opponent']] = df2[['opponent', 'team']]
df2['venue'] = df2['venue'].map({'Home': 'Away', 'Away': 'Home})
out = pd.concat([df, df2])
print(out)
Output:
match team opponent venue
233 3b0345fb Brazil Argentina Home
234 3b2357fb Argentina Brazil Away
427 3b0947fb England Poland Home
427 3b0947fb Poland England Away
If you want to invert all:
df2 = df.copy()
df2[['team', 'opponent']] = df2[['opponent', 'team']]
df2['venue'] = df2['venue'].map({'Home': 'Away', 'Away': 'Home})
out = pd.concat([df, df2])
output:
match team opponent venue
233 3b0345fb Brazil Argentina Home
234 3b2357fb Argentina Brazil Away
427 3b0947fb England Poland Home
233 3b0345fb Argentina Brazil Away
234 3b2357fb Brazil Argentina Home
427 3b0947fb Poland England Away