Daniel Huppmann

Thanks Jan Ivar for that comment. Can you explain a bit further what your vision for the "working further in Python with the invalid items" actually is? I'm a bit...

I'd still be curious to better understand your intended use case. But yes, happy to review a PR and provide feedback - please create a fork and tinker away...

PR https://github.com/openENTRANCE/openentrance/pull/296 ran into a similar issue, where the region-mapping fails unless a directional region code `Austria>Germany` is not stated explicitly in the mapping. Possible solutions for the **region-validation**: -...

I would fill that at run-time - for the list of countries, this might still be possible (but duplicating) to create a yaml from the pycountry package. But for datetime-validation,...

I think that makes a lot of sense. Having optional data without constraints wouldn't have any effect, but it's probably better to keep the same structure between the *required* and...

It was originally intended to store the dimension of the CodeList (region, variable, scenario). Given that we will not have dedicated sub-classes for all possible dimensions (because a user could...

Thanks @byersiiasa - this tutorial should still work, but I'm very skeptical whether we want to highlight this approach as part of the documentation...

Yes, I would move to "description" as the default in new projects, this is also in line with the documentation [here](https://github.com/IAMconsortium/nomenclature/blob/main/doc/source/user_guide/variable.rst). However, some (legacy) projects have neither of the two,...

For the pyam `aggregate()`-method, the pyam docs (see [here](https://pyam-iamc.readthedocs.io/en/stable/api/iamdataframe.html#pyam.IamDataFrame.aggregate)) make clear that missing values (components) is interpreted as 0. The `aggregate_region()` follows the same logic (but without an explicit note...

Let's revisit the discussion after merging #99