For the error you got attribute error in grade function.
While recalling the column TRTMT, please use X_train argument to the column as X_train.TRTMT==True for patient who received treatment and who didn’t receive as False. Because you recalled column variable TRTMT as a string object, this error was thrown.
Also in the subsequent code where you are suppose to drop this column TRTMT use here the string object function.
Let me know if the error is resolved.
Extremely sorry for the delayed response and unavailability due to personal issues.
Regards
DP