Drop Python 3.9

.github/workflows/main.yml

@@ -148,10 +148,6 @@ jobs:
           environment-file: environment-dev.yml
           create-args: >-
             python=${{ matrix.python-version }}
-      - name: Downgrade intake-esm
-        if: matrix.python-version == '3.9'
-        run: |
-          micromamba install -y -c conda-forge intake-esm=2023.11.10
       - name: Conda and Mamba versions
         run: |
           echo "micromamba $(micromamba --version)"

.pre-commit-config.yaml

@@ -6,7 +6,7 @@ repos:
     rev: v3.17.0
     hooks:
       - id: pyupgrade
-        args: [ '--py39-plus' ]
+        args: [ '--py310-plus' ]
   - repo: https://github.com/pre-commit/pre-commit-hooks
     rev: v4.6.0
     hooks:
@@ -21,7 +21,6 @@ repos:
       - id: check-toml
       - id: check-yaml
         args: [ '--allow-multiple-documents' ]
-        exclude: conda/xscen/meta.yaml
   - repo: https://github.com/pre-commit/pygrep-hooks
     rev: v1.10.0
     hooks:
@@ -77,10 +76,10 @@ repos:
     rev: 1.8.5
     hooks:
       - id: nbqa-pyupgrade
-        args: [ '--py39-plus' ]
+        args: [ '--py310-plus' ]
         additional_dependencies: [ 'pyupgrade==3.17.0' ]
       - id: nbqa-black
-        args: [ '--target-version=py39' ]
+        args: [ '--target-version=py310' ]
         additional_dependencies: [ 'black==24.8.0' ]
       - id: nbqa-isort
         additional_dependencies: [ 'isort==5.13.2' ]

.yamllint.yaml

@@ -37,6 +37,3 @@ rules:
   trailing-spaces: {}
 
   truthy: disable
-
-ignore: |
-  conda/xscen/meta.yaml

CHANGELOG.rst

@@ -42,6 +42,7 @@ Breaking changes
 ^^^^^^^^^^^^^^^^
 * `convert_calendar` in ``clean_up`` now uses `xarray` instead of `xclim`. Keywords aren't compatible between the two, but given that `xclim` will abandon its function, no backwards compatibility was sought. (:pull:`450`).
 * `attrs_to_remove` and `remove_all_attrs_except` in ``clean_up`` now use real regex. It should not be too breaking since a `fullmatch()` is used, but `*` is now `.*`. (:pull:`450`).
+* Python 3.9 is no longer supported. (:pull:`456`).
 
 Internal changes
 ^^^^^^^^^^^^^^^^

CONTRIBUTING.rst

@@ -257,7 +257,7 @@ Before you submit a pull request, check that it meets these guidelines:
 
 #. The pull request should not break the templates.
 
-#. The pull request should work for all currently supported Python versions. Check the `pyproject.toml` or `tox.ini` files for the list of supported versions.
+#. The pull request should work for all currently supported Python versions. Check the `pyproject.toml` or `tox.ini` files for the list of supported versions. We aim to follow the support and drop schedule of Python versions as recommended by the NumPy NEP calendar: https://numpy.org/neps/nep-0029-deprecation_policy.html
 
 Tips
 ----

environment-dev.yml

@@ -2,7 +2,7 @@ name: xscen-dev
 channels:
   - conda-forge
 dependencies:
-  - python >=3.9,<3.13
+  - python >=3.10,<3.13
   # Don't forget to sync changes between environment.yml, environment-dev.yml, and pyproject.toml!
   # Also consider updating the list in xs.utils.show_versions if you add a new package.
   # Main packages
@@ -15,24 +15,24 @@ dependencies:
   - fsspec
   - geopandas
   - h5netcdf
-  - h5py <3.11 # writting and reading with engine h5netcdf was broken
+  - h5py <3.11 # writing and reading with engine h5netcdf was broken
   - intake-esm >=2023.07.07
-  - matplotlib
-  - netCDF4 <1.7 # writting and reading with engine h5netcdf was broken
+  - matplotlib >=3.6
+  - netCDF4 <1.7 # writing and reading with engine h5netcdf was broken
   - numcodecs
-  - numpy
+  - numpy >=1.24,<2.0  # v2.0 is not supported by python-netcdf4
   - pandas >=2.2
   - parse
   - pyyaml
   - rechunker
-  - scipy
+  - scipy >=1.10
   - shapely >=2.0
   - sparse
   - toolz
-  - xarray >=2023.11.0, !=2024.6.0, <2024.09.0
-  - xclim >=0.50, <0.51
+  - xarray >=2023.11.0, !=2024.6.0
+  - xclim >=0.52.2, <0.53
   - xesmf >=0.7
-  - zarr
+  - zarr >=2.13
   # Opt
   - nc-time-axis >=1.3.1
   - pyarrow >=10.0.1

environment.yml

@@ -2,7 +2,7 @@ name: xscen
 channels:
   - conda-forge
 dependencies:
-  - python >=3.9,<3.13
+  - python >=3.10,<3.13
   # Don't forget to sync changes between environment.yml, environment-dev.yml, and pyproject.toml!
   # Also consider updating the list in xs.utils.show_versions if you add a new package.
   # Main packages
@@ -15,24 +15,24 @@ dependencies:
   - fsspec
   - geopandas
   - h5netcdf
-  - h5py <3.11
+  - h5py <3.11 # writing and reading with engine h5netcdf was broken
   - intake-esm >=2023.07.07
-  - matplotlib
-  - netCDF4 <1.7
+  - matplotlib >=3.6
+  - netCDF4 <1.7 # writing and reading with engine h5netcdf was broken
   - numcodecs
-  - numpy
+  - numpy >=1.24,<2.0  # v2.0 is not supported by python-netcdf4
   - pandas >=2.2
   - parse
   - pyyaml
   - rechunker
-  - scipy
+  - scipy >=1.10
   - shapely >=2.0
   - sparse
   - toolz
-  - xarray >=2023.11.0, !=2024.6.0, <2024.09.0
-  - xclim >=0.50, <0.51
+  - xarray >=2023.11.0, !=2024.6.0
+  - xclim >=0.52.2, <0.53
   - xesmf >=0.7
-  - zarr
+  - zarr >=2.13
   # To install from source
   - setuptools >=65.0.0
   - setuptools-scm >=8.0.0