Pandas – return value of column

I have a df with categories and thresholds:

cat t1 t2 t3 t4
a   2  4  6  8
b   3  5  7  0
c   0  0  1  0

My end goal is to return the column name given category and score. I can select a row using a cat variable:

df[df['cat'] == cat]

How do I now return the column name that is closest to the score (rounded down)? (c, 3) -> t3

>Solution :

You can compute the absolute difference to your value and get the index of the minimum with idxmin:

value = 3
cat = 'c'

(df.set_index('cat')
   .loc[cat]
   .sub(value).abs()
   .idxmin()
 )

Output: 't3'