pandas series repeat n time and change column value

Question

I have input data like this.

NAME | PLACE | DATE
  A  |   X   | 2020-04-30
  B  |   Y   | 2019-04-30

i want to duplicate 5 times and change d

Answer 1

Here is a way to do it:

df_out = df.reindex(df.index.repeat(6))

df_out['DATE'] += pd.Series([pd.DateOffset(years=i) 
                              for i in df_out.groupby('AME').cumcount()], 
                            index=df_out.index)    
df_out.reset_index(drop=True)

Output:

      AME    PLACE       DATE
0     A       X    2020-04-30
1     A       X    2021-04-30
2     A       X    2022-04-30
3     A       X    2023-04-30
4     A       X    2024-04-30
5     A       X    2025-04-30
6     B       Y    2019-04-30
7     B       Y    2020-04-30
8     B       Y    2021-04-30
9     B       Y    2022-04-30
10    B       Y    2023-04-30
11    B       Y    2024-04-30