Check if value stays the same for 10 consecutive days

You can get the last value for groups of consecutive days, identical groups, and values using the following steps:

1. Ensure datetime:

df['Date'] = pd.to_datetime(df['Date'])
  

2. Ensure data is sorted by groups, then date:

tmp = df.sort_values(by=['X', 'Y', 'Date'])
  

3. Form groups of consecutive data:

group = (tmp['Date'].diff().ne(pd.Timedelta(days=1))
         |
         tmp[['X', 'Y', 'Value']]
         .ne(tmp[['X', 'Y', 'Value']].shift())
         .any(axis=1)
        ).cumsum()
  

4. Form grouper:

g = df.groupby(group)
  

5. Get last row (date) per group:

out = g.last()[g.size().ge(N_days)]
  

6. Print the output:

print(out)
  

Output:

        Date   X    Y  Value
9 2024-01-20  X2  456      4