部分字符串与 str.contains 匹配，使用 dict comprehension with python/pandas

Question

I have a data frame with a column called course_names with a mapping dictionary with a list of course names i'd like to match in the key and the value I would want to assign in the value column

import pandas as pd
df = pd.DataFrame({'course_name' : ['Phsyics, Maths','Algebra & Maths','History','Geology','Biology']})


mapping = {'Algebra & Maths' : 'Mathematics',
'Phsyics' : 'Science',
'History' : 'History',
'Geology' : 'Geology',
'Biology' : 'Science'} 
# this goes on for about another 35 lines. 

#my attempt so far.

df['keys'] = [k for k, v in mapping.items() if df['course_name'] in k]

when I run this code I get :

TypeError: 'in <string>' requires string as left operand, not Series

expected output :

    course_name          key
0   Phsyics, Maths      Science
1  Algebra & Maths  Mathematics
2          History      History
3          Geology      Geology
4          Biology      Science

Answer 1

You had a small syntax error. You can also use map

Try:

import pandas as pd
df = pd.DataFrame({"course_name" : ["Algebra & Maths", "Phsyics"]})
Mapping = {'Algebra & Maths' : 'Mathematics','Phsyics' : 'Science'}
df["keys"] = [v for k, v in Mapping.items() if k in df['course_name'].tolist()]
#df["keys"] = df["course_name"].map(Mapping)
print(df)

Output:

       course_name         keys
0  Algebra & Maths  Mathematics
1          Phsyics      Science