ESMValGroup · valeriupredoi · Jan 5, 2026 · Jan 5, 2026 · Jan 5, 2026 · Jan 5, 2026
@@ -33,6 +33,7 @@ jobs:
         environment:
           - test-py312
           - test-py313
+          - test-py314
     name: ${{ matrix.os }} ${{ matrix.environment }}
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

@@ -29,6 +29,7 @@ jobs:
         environment:
           - test-py312
           - test-py313
+          - test-py314
     name: ${{ matrix.os }} ${{ matrix.environment }}
     steps:
       - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2

@@ -12,6 +12,10 @@
 Download and processing instructions
     Download the following file:
     https://aeronet.gsfc.nasa.gov/data_push/V3/AOD/AOD_Level20_Monthly_V3.tar.gz
+
+NOTE this formatter is currently not working for Python 3.14 since pys2index is
+not supported under Python 3.14! You will have to use Python<3.14, and install pys2index
+from conda-forge.
 """
 
 import logging

@@ -14,6 +14,10 @@
     https://gml.noaa.gov/aftp/data/trace_gases/ch4/flask/surface/ch4_surface-flask_ccgg_text.tar.gz
     https://gml.noaa.gov/aftp/data/trace_gases/co2/flask/surface/co2_surface-flask_ccgg_text.tar.gz
     https://gml.noaa.gov/aftp/data/trace_gases/n2o/flask/surface/n2o_surface-flask_ccgg_text.tar.gz
+
+NOTE this formatter is currently not working for Python 3.14 since pys2index is
+not supported under Python 3.14! You will have to use Python<3.14, and install pys2index
+from conda-forge.
 """
 
 import logging

@@ -12,6 +12,10 @@
 Download and processing instructions
     Download the following file:
     https://gml.noaa.gov/aftp/data/trace_gases/ch4/flask/surface/ch4_surface-flask_ccgg_text.tar.gz
+
+NOTE this formatter is currently not working for Python 3.14 since pys2index is
+not supported under Python 3.14! You will have to use Python<3.14, and install pys2index
+from conda-forge.
 """
 
 from esmvaltool.cmorizers.data.formatters.datasets import (

@@ -12,6 +12,10 @@
 Download and processing instructions
     Download the following file:
     https://gml.noaa.gov/aftp/data/trace_gases/co2/flask/surface/co2_surface-flask_ccgg_text.tar.gz
+
+NOTE this formatter is currently not working for Python 3.14 since pys2index is
+not supported under Python 3.14! You will have to use Python<3.14, and install pys2index
+from conda-forge.
 """
 
 from esmvaltool.cmorizers.data.formatters.datasets import (

@@ -12,6 +12,10 @@
 Download and processing instructions
     Download the following file:
     https://gml.noaa.gov/aftp/data/trace_gases/n2o/flask/surface/n2o_surface-flask_ccgg_text.tar.gz
+
+NOTE this formatter is currently not working for Python 3.14 since pys2index is
+not supported under Python 3.14! You will have to use Python<3.14, and install pys2index
+from conda-forge.
 """
 
 from esmvaltool.cmorizers.data.formatters.datasets import (

diff --git a/pixi.lock b/pixi.lock
diff --git a/pyproject.toml b/pyproject.toml
@@ -16,6 +16,7 @@ classifiers = [
     "Programming Language :: Python :: 3",
     "Programming Language :: Python :: 3.12",
     "Programming Language :: Python :: 3.13",
+    "Programming Language :: Python :: 3.14",
     "Topic :: Scientific/Engineering",
     "Topic :: Scientific/Engineering :: Atmospheric Science",
     "Topic :: Scientific/Engineering :: GIS",
@@ -59,7 +60,7 @@ dependencies = [
     "pandas",
     "progressbar2",
     "pyproj>=2.1",
-    "pys2index",
+    #  "pys2index",
     "python-dateutil",
     "pyyaml",
     "rasterio>=1.3.10",
@@ -81,7 +82,7 @@ description = "A community tool for pre-processing data from Earth system models
 license = "Apache-2.0"
 license-files = ["LICENSE", "NOTICE"]
 name = "ESMValTool"
-requires-python = ">=3.12,<3.14"
+requires-python = ">=3.12,<3.15"
 
 [project.entry-points."console_scripts"]
 nclcodestyle = "esmvaltool.utils.nclcodestyle.nclcodestyle:_main"
@@ -244,7 +245,7 @@ convention = "numpy"
 "progressbar2" = "*"
 "prov" = "*"
 "pyproj" = ">=2.1"
-"pys2index" = "*"
+#  "pys2index" = "*"
 "python" = ">=3.12"
 "python-cdo" = "*"
 "python-dateutil" = "*"
@@ -296,7 +297,8 @@ esmvaltool = { features = ["esmvalcore", "ncl", "r"], solve-group = "esmvaltool"
 esmvalcore-dev = { features = ["esmvalcore-dev", "dev", "doc", "test"], solve-group = "esmvalcore-dev" }
 # Environments for running tests with specific Python versions.
 test-py312 = { features = ["py312", "esmvalcore", "test"], solve-group = "py312" }
-test-py313 = { features = ["py313", "esmvalcore", "test"], solve-group = "default" }
+test-py313 = { features = ["py313", "esmvalcore", "test"], solve-group = "py313" }
+test-py314 = { features = ["py314", "esmvalcore", "test"], solve-group = "default" }
 
 # Default ESMValCore version.
 [tool.pixi.feature.esmvalcore.dependencies]
@@ -342,6 +344,10 @@ test-py313 = { features = ["py313", "esmvalcore", "test"], solve-group = "defaul
 [tool.pixi.feature.py313.dependencies]
 "python" = "3.13.*"
 
+# Feature for running tests with Python 3.14.
+[tool.pixi.feature.py314.dependencies]
+"python" = "3.14.*"
+
 # Feature for running diagnostics that also require NCL.
 [tool.pixi.feature.ncl]
 platforms = ["linux-64"]

diff --git a/tests/unit/cmorizers/test_cmorization_interface.py b/tests/unit/cmorizers/test_cmorization_interface.py
@@ -20,8 +20,22 @@ def test_formatters_have_required_interface():
 
     error = False
 
-    for formatter in os.listdir(formatters_folder):
-        if not formatter.endswith(".py") or formatter == "__init__.py":
+    # aeronet.py and noaa_gml_surface_flask*.py need pys2index
+    do_not_run_formatters = [
+        "__init__.py",
+        "aeronet.py",
+        "noaa_gml_surface_flask.py",
+        "noaa_gml_surface_flask_ch4.py",
+        "noaa_gml_surface_flask_co2.py",
+        "noaa_gml_surface_flask_n2o.py",
+    ]
+    all_formatters = os.listdir(formatters_folder)
+    to_run_formatters = [
+        f for f in all_formatters if f not in do_not_run_formatters
+    ]
+
+    for formatter in to_run_formatters:
+        if not formatter.endswith(".py"):
             continue
         module = formatter[:-3]
         member = importlib.import_module(