I aim to create a new column based on multiple string matches. This new column will return a 1 number for every match on the event column.
Date Event
0 2022-11-01 Breakfast
1 2022-11-01 Breakfast
2 2022-11-01 Lunch
3 2022-11-02 Breakfast
4 2022-11-02 Lunch
After
Date Event Breakfast Lunch
0 2022-11-01 Breakfast 1 null
1 2022-11-01 Breakfast 1 null
2 2022-11-01 Lunch null 1
3 2022-11-02 Breakfast 1 null
4 2022-11-02 Lunch null 1
You can use pd.get_dummies for the task:
out = pd.concat([df, pd.get_dummies(df['Event'])], axis=1)
print(out)
Prints:
Date Event Breakfast Lunch
0 2022-11-01 Breakfast 1 0
1 2022-11-01 Breakfast 1 0
2 2022-11-01 Lunch 0 1
3 2022-11-02 Breakfast 1 0
4 2022-11-02 Lunch 0 1
If you want None instead 0:
out = out.replace({0: None})
print(out)
Prints:
Date Event Breakfast Lunch
0 2022-11-01 Breakfast 1 None
1 2022-11-01 Breakfast 1 None
2 2022-11-01 Lunch None 1
3 2022-11-02 Breakfast 1 None
4 2022-11-02 Lunch None 1