geojsoncontour's contourf_to_geojson issue

[charlienegri]

the contourf_to_geojson function call (see https://github.com/metno/pyaerocom/blob/main-dev/pyaerocom/aeroval/modelmaps_helpers.py#L90) fails with the version of the code tagged cams2-83_2024-12.1 (at least for the "onlymap" runs of cams2_83) with the following error

│ /modules/rhel8/user-apps/fou-modules/cams2_83-evaluation/2024-12.1/venv/lib/ │
│ python3.10/site-packages/geojsoncontour/contour.py:81 in contourf_to_geojson │
│                                                                              │
│    78 │   │   variable_opacity = False                                       │
│    79 │   polygon_features = []                                              │
│    80 │   contourf_levels = get_contourf_levels(contourf.levels, contourf.ex │
│ ❱  81 │   for coll, level in zip(contourf.collections, contourf_levels):     │
│    82 │   │   color = coll.get_facecolor()                                   │
│    83 │   │   muli = MP(coll, min_angle_deg, ndigits)                        │
│    84 │   │   polygon = muli.mpoly()                                         │
│                                                                              │
│ ╭───────────────────────────────── locals ─────────────────────────────────╮ │
│ │           contourf = <cartopy.mpl.contour.GeoContourSet object at        │ │
│ │                      0x14e3f3e20760>                                     │ │
│ │    contourf_levels = [                                                   │ │
│ │                      │   '100.00-125.00',                                │ │
│ │                      │   '125.00-150.00',                                │ │
│ │                      │   '150.00-175.00',                                │ │
│ │                      │   '175.00-200.00',                                │ │
│ │                      │   '200.00-225.00',                                │ │
│ │                      │   '225.00-250.00',                                │ │
│ │                      │   '250.00-275.00',                                │ │
│ │                      │   '275.00-300.00',                                │ │
│ │                      │   '>300.00'                                       │ │
│ │                      ]                                                   │ │
│ │       fill_opacity = 0.9                                                 │ │
│ │ fill_opacity_range = None                                                │ │
│ │   geojson_filepath = None                                                │ │
│ │ geojson_properties = None                                                │ │
│ │      min_angle_deg = None                                                │ │
│ │            ndigits = 5                                                   │ │
│ │   polygon_features = []                                                  │ │
│ │          serialize = True                                                │ │
│ │            strdump = False                                               │ │
│ │       stroke_width = 1                                                   │ │
│ │               unit = ''                                                  │ │
│ │   variable_opacity = False                                               │ │
│ ╰──────────────────────────────────────────────────────────────────────────╯ │
╰──────────────────────────────────────────────────────────────────────────────╯
AttributeError: 'GeoContourSet' object has no attribute 'collections'

I wonder if this might be due to a newer version of geojsoncontour...
in the module where this issue showed up (installed as pip install --force "git+ssh://[email protected]/metno/pyaerocom.git@cams2-83_2024-12.1") I have gotten

Cartopy                        0.24.1
contourpy                      1.3.1
geojson                        3.1.0
geojsoncontour                 0.4.0
matplotlib                     3.10.0
pyproj                         3.7.0

[charlienegri]

as Magnus suggested, this is a geojsoncontour + matplotlib issue https://chat.google.com/room/AAAAvubjk88/wil_lmXeOd8/jkubBxfSPiw?cls=12
pinning matplotlib to < 3.10.0 would be a workaround before geojson is fixed

[magnusuMET]

See https://discourse.matplotlib.org/t/collections-attribute-deprecation-in-version-3-8/24164 for some discussion on how to fix this (in geojsoncontour)

[magnusuMET]

See bartromgens/geojsoncontour#27 for a potential fix

[lewisblake]

TODO

1. release new version of geojsoncontour
2. Unpin matplotlib
3. Test this resolves the issue above