I have a df with with several columns which have only True/False values.
I want to create another column whose value will tell me which column has a `True` value.
HEre's an example:

| index | bol\_1 | bol\_2 | bol\_3 | criteria |
| --- | --- | --- | --- | --- |
| 1 | True | False | False | `bol_1` |
| 2 | False | True | False | `bol_2` |
| 3 | True | True | False | [`bol_1`, `bol_2`] |

My objective is to know which rows have True values(at least 1), and which columns are responsible for those True values. I want to be able to some basic statistics on this new column, e.g. for how many rows is bol\_1 the unique column to have a True values.