從數據框中，如何按列分組並附加結果以創建新的數據框？

Question

請看一下我的代碼好嗎？
這是（部分）我的 DF

display(count_df)

    title
0   Programmer
1   Oracle Fusion/ EBS Developer
2   Software Engineer RH-22-07
3   Web Developer E-Commerce
4   Software Engineer
5   Junior Front-End Developer/Designer
6   Programmer Analyst (Giampaolo Group - Hybrid W...
7   Full Stack Developer
8   SAS/SQL Programmer
9   AWS Cloud Architect
10  Full Stack Software Engineer
11  Full Stack .Net Developer (Independent Contrac...

這是我得到的結果

#Create a new column called 'counts', and then group by the times the title appears within the column
count_df['counts'] = count_df.groupby('title')['title'].transform('count')
print(count_df.value_counts())

title                                                         counts
AWS Cloud Architect                                           4         4
Programmer                                                    4         4
Web Developer E-Commerce                                      4         4
Software Engineer                                             4         4
SAS/SQL Programmer                                            4         4
Full Stack .Net Developer (Independent Contractor)            4         4
Web developer                                                 4         4
Junior Front-End Developer/Designer                           4         4
Intermediate Software Developer                               4         4
Full Stack Software Engineer                                  4         4
Full Stack Developer                                          4         4
Junior Java Developer (Recent Graduate)                       3         3
Software Developer                                            3         3
Software Developer, Co-Op (Sept-Dec)                          3         3
Software Engineer with Test                                   3         3
Oracle Fusion/ EBS Developer                                  1         1
React Developer (3 Month Contract)                            1         1
Software Engineer RH-22-07                                    1         1
Programmer Analyst (Giampaolo Group - Hybrid Work From Home)  1         1

最后，我需要的結果就是這個，但是作為一個新的DF。

title                                                         counts
AWS Cloud Architect                                           4         
Programmer                                                    4         
Web Developer E-Commerce                                      4         
Software Engineer                                             4         
SAS/SQL Programmer                                            4         
Full Stack .Net Developer (Independent Contractor)            4         
Web developer                                                 4         
Junior Front-End Developer/Designer                           4
Intermediate Software Developer                               4
Full Stack Software Engineer                                  4
Full Stack Developer                                          4
Junior Java Developer (Recent Graduate)                       3         
Software Developer                                            3         
Software Developer, Co-Op (Sept-Dec)                          3         
Software Engineer with Test                                   3         
Oracle Fusion/ EBS Developer                                  1         
React Developer (3 Month Contract)                            1         
Software Engineer RH-22-07                                    1         
Programmer Analyst (Giampaolo Group - Hybrid Work From Home)  1         

我認為復制“計數”列的是代碼“print（count_df.value_counts（））”的這一部分，但沒有它，我不會得到預期的結果。

謝謝你。

Answer 1

我認為重復這些列的原因是您將結果分配給 DataFrame 的新列而不是新的 DataFrame。

嘗試這個：

count_df2 = count_df.groupby('title')['title'].size().sort_values(ascending=False).reset_index(name='counts')

或這個：

count_df2 = count_df.groupby('title')['title'].agg('count').sort_values(ascending=False).reset_index(name='counts')