Multi-Indexing

Just like in excel, you can have multi indexing columns for a table.

Level and Columns

reset_index transform existing indices to columns

set_index transform columns to indices

• set_index(..., append=True) will add a new level index.
• If False it will discard all levels except the new one.

This name is really intuitive, set_index vs reset_index

Order levels

You can use swaplevel to change order of levels.

Name the levels

Groupby and aggregates

groupby

• You can group by columns or levels but you can only use one, not both
  • groupby(by=[...])
  • groupby(level=(0,1,2))