add_prefix() : prefix columns

Using DataFrame

import pandas as pd 
my_dict={'NAME':['Ravi','Raju','Alex','Ron','King','Jack'],
         'ID':[1,2,3,4,5,6],'MATH':[30,40,50,60,70,80],
         'ENGLISH':[20,30,40,50,60,70]}
my_data = pd.DataFrame(data=my_dict)
my_data=my_data.add_prefix('Col_')
print(my_data)

  Col_NAME  Col_ID  Col_MATH  Col_ENGLISH
0     Ravi       1        30           20
1     Raju       2        40           30
2     Alex       3        50           40
3      Ron       4        60           50
4     King       5        70           60
5     Jack       6        80           70

Using series

my_s=pd.Series([1,5,7,9,10])
my_s=my_s.add_prefix('Ser_')
print(my_s)

Ser_0     1
Ser_1     5
Ser_2     7
Ser_3     9
Ser_4    10
dtype: int64