如何基于其他现有列的条件添加具有值的新列？

Question

This is the current df_treatments.

I want to add a new field "treatment_type" with values that should be based on the values in columns (metformin, glipizide, insulin):

("value of treatment_type": (value of metformin,value of glipizide, value of insulin))

"No Treatment" (NO, NO, NO)
"Metformin" (YES, NO, NO)
"Glipizide" (NO, YES, NO)
"Insulin" (NO, NO, YES)
"Metformin-Glipizide" (YES, YES, NO)
"Metformin-Insulin" (YES, NO, YES)
"Glipizide-Insulin" (NO, YES, YES)
"Metformin-Glipizide-Insulin" (YES, YES, YES)

How can I do this?

Thank you,

Answer 1

There are a few approaches. One is to use a dictionary to store your treatments and conditions:

d = {"No Treatment": ('NO', 'NO', 'NO'),
     "Metformin": ('YES', 'NO', 'NO')
     "Glipizide": ('NO', 'YES', 'NO'),
     ...}

Then iterate your dictionary and update your series:

arr = df[['metformin', 'glipizide', 'insulin']].values

for treatment, flags in d.items():
    df.loc[(arr == flags).all(1), 'treatment_type'] = treatment

The only improvement I suggest is to convert all 'NO' / 'YES' values to Boolean False / True . This will be considerably more efficient as Boolean series support vectorised operations.