在列中添加具有累积唯一值计数的列

Question

I'm trying to add a column with the number of unique values appearances, so if my input is:

id  |  score
 asd    15
 asd    20
 jk     76
 pz     54
 pz     37

I want to add a column like this

 id  | score  | count_ids
 asd    15           1
 asd    20           1
 jk     76           2
 pz     54           3
 pz     37           3

I've seen this answer Pandas add unique count column , although I feel like there should be a neater solution to this.

Edit

I'm also looking for a scalable solution, so for example, if I also have this:

 id  |  game  |  score
 asd    1          15
 asd    2          20
 jk     1          76
 pz     1          54
 pz     1          37

Get

 id  |  game  |  score  | count_users
 asd    1          15         1
 asd    2          20         2
 jk     1          76         3
 pz     1          54         4
 pz     1          37         4

Answer 1

I think solution should be simplify without helper column:

df['count_ids'] = df['id'].ne(df['id'].shift()).cumsum()
print (df)
    id  score  count_ids
0  asd     15          1
1  asd     20          1
2   jk     76          2
3   pz     54          3
4   pz     37          3

EDIT: For multiple columns solution is similar, only add DataFrame.any for test at least one True per row:

df['count_ids'] = df[['id', 'game']].ne(df[['id', 'game']].shift()).any(axis=1).cumsum()
print (df)

    id  game  score  count_ids
0  asd     1     15          1
1  asd     2     20          2
2   jk     1     76          3
3   pz     1     54          4
4   pz     1     37          4

Detail :

print (df[['id', 'game']].ne(df[['id', 'game']].shift()))
      id   game
0   True   True
1  False   True
2   True   True
3   True  False
4  False  False