Individual NUTS level definition not working in `clustering.administrative.countries` config setting

[gianvicolux]

Version Checks (indicate both or one)

• I have confirmed this bug exists on the lastest release of PyPSA-Eur.

• I have confirmed this bug exists on the current master branch of PyPSA-Eur.

Issue Description

Specifying the individual NUTS levels for some countries as a dictionary in clustering.administrative.countries config setting, seems not to working as expected in the clustering documentation.

In particular, the level defined in clustering.administrative.level is applied also to the countries in clustering.administrative.countries , despite they have a different level.

This seems to be due to this part of code in build_admin_shapes in base_network.py:

country_level = {
         k: v for k, v in admin_levels.items() if (k != "level") and (k in countries)
}

Instead, it might work changing it into:

country_level = {
         k: v for k, v in admin_levels.get("countries", {}).items()
         if k in countries
}

Reproducible Example

When using this setting:

clustering:
  mode: administrative
  administrative:
    level: bz
    countries: {'DE': 2}

and checking the admin_shapes.geojson:

admin_shapes = gpd.read_file("[...]/admin_shapes.geojson")
display(admin_shapes[admin_shapes["country"] == "DE"].admin)

one would see DE00.

Expected Behavior

When using this setting:

clustering:
  mode: administrative
  administrative:
    level: bz
    countries: {'DE': 2}

and checking the admin_shapes.geojson:

admin_shapes = gpd.read_file("[...]/admin_shapes.geojson")
display(admin_shapes[admin_shapes["country"] == "DE"].admin)

one would expect:

DE11
DE12
...
DEG0

Installed Versions

Too long to post.