How to convert a DataFrame with repeated indices into a MultiIndex DataFrame?

Question

I'm trying to convert DataFrame that looks like this:

    i  j  n
1   1  2  #
2   1  3  #
3   1  5  #
4   2  1  #
5   2  2  #
6   2  4  #
7   3  5  #
8   3  6  #

to a MultiIndex DataFrame like this:

      n
1  2  #
   3  #
   5  #
2  1  #
   2  #
   4  #
3  5  #
   6  #

I don't want to go row by row and inserting into a new DataFrame and I'm sure that there's a quicker way anyway.

Answer 1

Welp，我最初误解了文档，解决方案非常简单： df.set_index(['i', 'j'])产生预期的效果。