要准确匹配您可以执行的所需输出

To match the exact desired output you could do

df['aux'] = df.groupby('rep').cumcount()
df.pivot(index='aux' ,columns='rep', values='student_id')

输出:

rep       1       2
aux                
0    abc100  abc101
1    abc102  abc103
2    abc104  abc105
3    abc106  abc107