PEtab lint requires indices

[PaulJonasJost]

I noticed that petab_lint requires for some tables specific indices (see e.g. check_observables_df line 301). I was wondering whether there is a specific reason for this or whether one could relax this to the corresponding column (in the example case observableId).

[dweindl]

The reason is mostly that it's somewhat annoying to deal with different inputs in every function.
If you load a PEtab problem using Problem.from_yaml, the index will be set correctly. If you want to load individual tables, you can use the get_XXX_df() functions, which will do the same. You can pass either a path or an existing DataFrame.