两个数据框之间的交叉检查？

Question

I have a df of students with numeric grades in different classes. Then, I have another df that that has a points scale for each class (thresholds)

Students  Math English
Josh       45    27
Max        23    37
Justin     34    13
Charles    56    27

Points scale

points  Math  English
  1      10     5
  2      20     10
  3      30     15
  4      40     20
  5      50     25

I want to assign points to different students from their grades for each class based off of the points scale

How can I make a dataframe that looks like this:

Students  Math English
Josh       4    5
Max        2    5
Justin     3    2
Charles    5    3

If someone has an English score of 16 for example, they would get 3 points, not 4.

Answer 1

Use cut for all columns without first with bins and labels used from df2 :

for c in df1.columns[1:]:
    df1[c] = pd.cut(df1[c], bins=df2[c].tolist() + [np.inf], labels=df2['points'])

print (df1)
  Students Math English
0     Josh    4       5
1      Max    2       5
2   Justin    3       2
3  Charles    5       5