Group by date range and check duplicate pandas

I am trying to see if I can find duplicate records happened in the year

I know how to find when it is just the year but the date range and find the duplicate and remove the duplicate seems a bit tough. I am beginner so pleas can anyone help ?

>Solution :

You can use:

out = df[~df.loc[df['Date'].str.contains('2021')].duplicated(keep=False)
            .reindex(df.index, fill_value=False)]
print(out)

# Output
         Date Transaction
0  31/12/2020   PURCHASES
1  31/12/2020       Sales
2  31/12/2020       Sales