如何根据评论找到每部电影的平均分数 - Python

Question

I have dataframe like this.

    UserID  Review      MovieID
0   10112   Good        MOV001
1   10112   Excellent   MOV002
2   10112   Average     MOV003
3   10113   Good        MOV001
4   10113   Bad         MOV002
5   10113   Good        MOV003
6   10113   Excellent   MOV004
7   10114   Good        MOV001
8   10114   Bad         MOV002
9   10114   Good        MOV003
10  10114   Excellent   MOV004

I've changed the reviews to int values.

movies.Review[movies.Status == 'Average'] = 2
movies.Review[movies.Status == 'Good'] = 3
movies.Review[movies.Status == 'Excellent'] = 5
movies.Review[movies.Status == 'Very Good'] = 4
movies.Review[movies.Status == 'Okay'] = 1
movies.Review[movies.Status == 'Bad'] = 0
movies

Now my dataframe will look like this,

UserID  Review      MovieID
0   10112   3           MOV001
1   10112   5           MOV002
2   10112   2           MOV003
3   10113   3           MOV001
4   10113   0           MOV002
5   10113   3           MOV003
6   10113   5           MOV004
7   10114   3           MOV001
8   10114   0           MOV002
9   10114   3           MOV003
10  10114   5           MOV004

Now how can I find the average score for each movie based on Review? Can anyone help me out?

Answer 1

First, you don't need those movies.Review[movies.Status==...] =... . Instead, use np.select or map :

Status_convert = {'Bad':0, 'Okay':1, 'Average':2,
                   'Good':3, 'Very Good':4, 'Excellent':5}
movies['Review'] = movies.Status.map(Status_convert)

Then you can do:

df.groupby('MovieID')['Review'].mean()

Output:

MovieID
MOV001    3.000000
MOV002    1.666667
MOV003    2.666667
MOV004    5.000000
Name: Review, dtype: float64