Get occurences of a value in column for current row and above

Question

I got a task i normally do in excel, and can't figure out how to convert in a smart way to Python. I have a dataframe roughly 700 rows and 30 columns, though only one column is relevant for this issue:

Column X
---------
A          1
A          1
A          1
A          1
A          1
A          1
A          1
A          1
A          1
A          1
A          1
A          0
A          0
A          0
A          0
A          0
B          1
B          1
B          1
B          1
B          1
B          1
B          1
B          1
B          1
B          1
B          1
B          0
B          0
B          0
C          1
C          1

I need to create a new column with the value 1, for the first 11 occurences of whatever is in column X, So the first 11 rows of "A" gets value 1 and the remaning ones gets 0. So i guess i can make a column that count occurences of df.at[idx, "Column X"], but only for current row and rows above. Once i have this i can make another column that writes 1 if the newly created column has a value of 11 or lower, and otherwise returns 0.

NB: Data is always sorted by X, so will follow the pattern shown above.

Any suggestions how this can be done?