Performing A Merge Function In Python, When I Don't Want The Values To Repeat

HI This is a follow up from one of my previous questions how do I perform a vlookup equivalent operation on my dataframe with some additional conditions As in the other question, m

Solution 1:

Use:

df_m = pd.merge(df, df2, on="product", how="left")

m = df_m["product"].isin(df2["product"]) & df_m["product"].eq(df_m["product"].shift())
df_m = df_m[~m].reset_index(drop=True)
print(df_m)

This prints:

     product  number to_add
0   Computer    1500NaN1         AA     232      Y
2    Monitor     300NaN3         BB    2323      N
4   Printer1     150NaN5         BB    2323      N
6       Desk     250NaN7         AA    2323      Y
8   Printer2      23NaN9         DD      34      N
10      Desk      45NaN11        BB      56      N