python - Easier way to fix pandas

Question

ID a b c d e f g
a  1 2 3 4 5 2 2
b  2 3 5 3 4 3 5 
c  2 3 4 2 4 2 4
a  2 3 4 2 5 2 5 
a  0 0 2 4 2 4 2
c  2 4 2 4 4 2 4

the goal is to create 4 new column based on c,d,e,f 
new_c = df.groupby('ID')['c'].transform('mean')
new_d = df.groupby('ID')['d'].transform('mean')
new_e = df.groupby('ID')['e'].transform('mean')
new_f = df.groupby('ID')['f'].transform('mean')

My code looks like below, but it doesn't allow me to use group by. Also, I want to append the new columns to the original df. Is there anyway to fix my code?

for col in df[2:-2]:
   res = df.groupby('ID')(df[col]).transform('mean')
return res

question from:https://stackoverflow.com/questions/66051485/easier-way-to-fix-pandas

Answer 1

Waitting for answers