python - 如何根据或/或比较合并 2 个数据帧？

Question

假设我有:

edu_data = [['school', 1, 2], ['college', 3, 4], ['grad-school', 5, 6]] 
edu = pd.DataFrame(edu_data, columns = ['Education', 'StudentID1', 'StudentID2']) 
print(edu)
     Education  StudentID1  StudentID2
0       school         1         2
1      college         3         4
2  grad-school         5         6

然后我有另一个表，其中包含人们的学生 ID:

data = [['tom', 3], ['nick', 5], ['juli', 6], ['jack', 10]] 
df = pd.DataFrame(data, columns = ['Name', 'StudentID']) 
print(df)
   Name  StudentID
0   tom        3
1  nick        5
2  juli        6
3  jack       10

我如何获得一个表，在该表中我将 df['StudentID'] 与 edu["StudentID1"] 或 edu["StudentID2"] 进行匹配。如果 df['StudentID'] 等于其中一个，那么我想将 edu["Education"] 附加到 df。

所以我希望我的输出是:

   Name  StudentID  Education
0   tom        3     college
1  nick        5     grad-school
2  juli        6     grad-school
3  jack       10     NaN

Answer 1

使用 map

s = edu.set_index('Education').stack().reset_index(level=1, drop=True)

df['Education'] = df.StudentID.map(pd.Series(s.index, s.values))

---

   Name  StudentID    Education
0   tom          3      college
1  nick          5  grad-school
2  juli          6  grad-school
3  jack         10          NaN