Input:
| memberid | serial | 
|---|---|
| 1 | A,B,C | 
| 2 | D,E | 
Python, pandas expected Output:
| memberid | serial | serial_no | 
|---|---|---|
| 1 | A,B,C | A | 
| 1 | A,B,C | B | 
| 1 | A,B,C | C | 
| 2 | D,E | D | 
| 2 | D,E | E | 
Input:
| memberid | serial | 
|---|---|
| 1 | A,B,C | 
| 2 | D,E | 
Python, pandas expected Output:
| memberid | serial | serial_no | 
|---|---|---|
| 1 | A,B,C | A | 
| 1 | A,B,C | B | 
| 1 | A,B,C | C | 
| 2 | D,E | D | 
| 2 | D,E | E | 
