السلام عليكم
 
	ده الكود
 
data_columns_nulls = data_train[['cyto_score','cyto_score_detail','hla_high_res_6','hla_high_res_8','hla_high_res_10']]
for columns in data_columns_nulls.columns:
    mean = data_train[columns].mean()
    print(f'{columns}: {mean}')
	ودي الخطاء
 
TypeError: unsupported operand type(s) for +: 'int' and 'str'