Split the entries in dataframe

here is my sample data:

df=pd.DataFrame({'Name':['A,B','C','D','E,F,G']
              ,'Age':[4,6,8,9]})

My expected output is to split the entries if there are more than one names.

pd.DataFrame({'Name':['A','B','C','D','E','F','G']
              ,'Age':[4,4,6,8,9,9,9]})

I can only split the name but I don’t now how to make it duplicated entries.
For first row, there are A,B under the Name, so I want to make it into two separate rows, A and B both are aged 4. Similarly, E,F,G are all aged at 9, so I want to convert this row into three rows with same age at 9.

df['Name'].apply(lambda x : x.split(','))

>Solution :

Combine df.set_index + str.split + explode:

df.set_index('Age')['Name'].str.split(',').explode().reset_index()

   Age Name
0    4    A
1    4    B
2    6    C
3    8    D
4    9    E
5    9    F
6    9    G