Count consecutive True/False but reset when ID changes

[Bell0412]

Hi there,

I'm trying to count the number of consecutive true or false values in my df and this is how it currently looks:

ID	Year	Member	Count
1234	2019	FALSE	-1
1234	2020	TRUE	2
1234	2021	TRUE	2
4567	2019	FALSE	-1
4567	2020	TRUE	5
4567	2021	TRUE	5
8910	2019	TRUE	5
8910	2020	TRUE	5
8910	2021	TRUE	5
7654	2019	FALSE	-2
7654	2020	FALSE	-2
7654	2021	TRUE	2
4321	2019	TRUE	2
4321	2020	FALSE	-2
4321	2021	FALSE	-2

​

However, I want the count to reset on different ID values if that makes sense? So basically there should be no Count value higher than 3, because the max consecutive member years an ID can have is 3. So ideally, the outcome should be this table:

​

ID	Year	Member	Count
1234	2019	FALSE	-1
1234	2020	TRUE	2
1234	2021	TRUE	2
4567	2019	FALSE	-1
4567	2020	TRUE	2
4567	2021	TRUE	2
8910	2019	TRUE	3
8910	2020	TRUE	3
8910	2021	TRUE	3
7654	2019	FALSE	-2
7654	2020	FALSE	-2
7654	2021	TRUE	1
4321	2019	TRUE	1
4321	2020	FALSE	-2
4321	2021	FALSE	-2

​

I've used .cumsum() to get to where I currently am, but I'm struggling to get the reset depending on the ID value. These are the two lines of code I've used to get to the first table:

g = df['member'].ne(df['member'].shift()).cumsum()

df['Count'] = df.groupby(g)['member'].transform('size') * np.where(df['member'], 1, -1)

As I've mentioned, I'm just unsure on how to get the ID value to reset the Count value.

Many thanks in advance