Python Pandas check dataframe groupby, how many people have the same book combinations

Question

So I have a list of people, each of them are given more than 2 books, 4 books are possible. I want to do a groupby and check frequency of combination of book received such as [ID, books] such ID: 1, he has Books: A, B I want to know how many people had received book combination of A and B.

Technically if someone has books A,B,C; he will have combination of (A,B),(A,C),(B,C),(A,B,C).

Input:

df = pd.DataFrame({'user': [1, 1, 2, 2, 3, 3, 3],
                   'disease': ['a', 'b', 'b', 'c', 'a', 'b', 'c']})[enter image description here][1]

enter image description here

Answer 1

You can use set operations.

Identify users with a given target combination:

target = {'a', 'b'}
df.groupby('user')['disease'].agg(lambda x: target.issubset(x))

Output:

user
1     True
2    False
3     True
Name: disease, dtype: bool

Count the number of users that match the target:

target = {'a', 'b'}
df.groupby('user')['disease'].agg(lambda x: target.issubset(x)).sum()

Output: 2