I have a Polars dataframe like so:
| c1 | c2 | c3 |
|---|---|---|
| a | a | 1 |
| a | a | 1 |
| a | b | 1 |
| a | c | 1 |
| d | a | 1 |
| d | b | 1 |
I am trying to assign a number to each group of (c2, c3) within c1, so that would look like this:
| c1 | c2 | c3 | rank |
|---|---|---|---|
| a | a | 1 | 0 |
| a | a | 1 | 0 |
| a | b | 1 | 1 |
| a | c | 1 | 2 |
| d | a | 1 | 0 |
| d | b | 1 | 0 |
How do I accomplish this?