Drop support for python 3.7 (#5892)

* remove requirement for setuptools.pkg_resources

Fixes #5676

Now depends on importlib-metadata for Python major version < 3.8

* doh

* doh2

* doh3, no reraise for fallback version number

* black formatting

* ordering

* all this lifetime wasted by fucking linting tools

* precommit

* remove python 3.7 as min supported version

* remove 3.7 from min_deps

* Update ci-additional.yaml

* test increasing dask

* test increasing numba

* Update ci-additional.yaml

* remove setuptools from CI

* undo dask/numba tests

* Remove importlib_metadata

* remove 3.7 compats

* Remove 3.7 compat

* remove sys

* Update options.py

* Update whats-new.rst

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* Run flaky/all but dask with latest python version

* fix all_but_dask file as well

* Update dataarray.py

* Update dataarray.py

* Update doc/whats-new.rst

Co-authored-by: keewis <keewis@users.noreply.github.com>

* update the install guide

* remove py37 only dependencies

* don't install importlib-metadata and typing_extensions into min-deps envs

* update the requirements file

* add back the optional typing_extensions dependency

Co-authored-by: Martin K. Scherer <m.scherer@fu-berlin.de>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>
Co-authored-by: keewis <keewis@users.noreply.github.com>
Co-authored-by: Keewis <keewis@posteo.de>

.github/workflows/ci-additional.yaml

@@ -40,10 +40,13 @@ jobs:
         os: ["ubuntu-latest"]
         env:
           [
-            "py37-bare-minimum",
-            "py37-min-all-deps",
-            "py38-all-but-dask",
-            "py38-flaky",
+            # Minimum python version:
+            "py38-bare-minimum",
+            "py38-min-all-deps",
+
+            # Latest python version:
+            "py39-all-but-dask",
+            "py39-flaky",
           ]
     steps:
       - uses: actions/checkout@v2
@@ -52,7 +55,7 @@ jobs:
 
       - name: Set environment variables
         run: |
-          if [[ ${{ matrix.env }} == "py38-flaky" ]] ;
+          if [[ ${{ matrix.env }} == "py39-flaky" ]] ;
           then
             echo "CONDA_ENV_FILE=ci/requirements/environment.yml" >> $GITHUB_ENV
             echo "PYTEST_EXTRA_FLAGS=--run-flaky --run-network-tests" >> $GITHUB_ENV
@@ -75,7 +78,7 @@ jobs:
           mamba-version: "*"
           activate-environment: xarray-tests
           auto-update-conda: false
-          python-version: 3.8
+          python-version: 3.9
           use-only-tar-bz2: true
 
       - name: Install conda dependencies
@@ -128,7 +131,7 @@ jobs:
           mamba-version: "*"
           activate-environment: xarray-tests
           auto-update-conda: false
-          python-version: "3.8"
+          python-version: "3.9"
 
       - name: Install conda dependencies
         run: |
@@ -164,10 +167,10 @@ jobs:
           channel-priority: strict
           mamba-version: "*"
           auto-update-conda: false
-          python-version: "3.8"
+          python-version: "3.9"
 
       - name: minimum versions policy
         run: |
           mamba install -y pyyaml conda python-dateutil
-          python ci/min_deps_check.py ci/requirements/py37-bare-minimum.yml
-          python ci/min_deps_check.py ci/requirements/py37-min-all-deps.yml
+          python ci/min_deps_check.py ci/requirements/py38-bare-minimum.yml
+          python ci/min_deps_check.py ci/requirements/py38-min-all-deps.yml

.github/workflows/ci.yaml

@@ -38,7 +38,7 @@ jobs:
       matrix:
         os: ["ubuntu-latest", "macos-latest", "windows-latest"]
         # Bookend python versions
-        python-version: ["3.7", "3.9"]
+        python-version: ["3.8", "3.9"]
     steps:
       - uses: actions/checkout@v2
         with:

ci/requirements/environment-windows.yml

@@ -36,7 +36,6 @@ dependencies:
   - rasterio
   - scipy
   - seaborn
-  - setuptools
   - sparse
   - toolz
   - typing_extensions

ci/requirements/environment.yml

@@ -40,7 +40,6 @@ dependencies:
   - rasterio
   - scipy
   - seaborn
-  - setuptools
   - sparse
   - toolz
   - typing_extensions

ci/requirements/py37-bare-minimum.yml → ci/requirements/py38-bare-minimum.yml

@@ -3,7 +3,7 @@ channels:
   - conda-forge
   - nodefaults
 dependencies:
-  - python=3.7
+  - python=3.8
   - coveralls
   - pip
   - pytest
@@ -12,5 +12,3 @@ dependencies:
   - pytest-xdist
   - numpy=1.18
   - pandas=1.1
-  - typing_extensions=3.7
-  - importlib-metadata=2.0

ci/requirements/py37-min-all-deps.yml → ci/requirements/py38-min-all-deps.yml

@@ -7,7 +7,7 @@ dependencies:
   # Run ci/min_deps_check.py to verify that this file respects the policy.
   # When upgrading python, numpy, or pandas, must also change
   # doc/installing.rst and setup.py.
-  - python=3.7
+  - python=3.8
   - boto3=1.13
   - bottleneck=1.3
   # cartopy 0.18 conflicts with pynio
@@ -24,7 +24,6 @@ dependencies:
   - hdf5=1.10
   - hypothesis
   - iris=2.4
-  - importlib-metadata=2.0
   - lxml=4.6  # Optional dep of pydap
   - matplotlib-base=3.3
   - nc-time-axis=1.2

ci/requirements/py38-all-but-dask.yml → ci/requirements/py39-all-but-dask.yml

@@ -3,7 +3,7 @@ channels:
   - conda-forge
   - nodefaults
 dependencies:
-  - python=3.8
+  - python=3.9
   - black
   - aiobotocore
   - boto3
@@ -36,7 +36,6 @@ dependencies:
   - rasterio
   - scipy
   - seaborn
-  - setuptools
   - sparse
   - toolz
   - typing_extensions

doc/getting-started-guide/installing.rst

@@ -6,11 +6,9 @@ Installation
 Required dependencies
 ---------------------
 
-- Python (3.7 or later)
-- `importlib_metadata <https://importlib_metadata.readthedocs.io/>`__ (1.4 or later, Python 3.7 only)
-- ``typing_extensions`` (3.7 or later, Python 3.7 only)
-- `numpy <http://www.numpy.org/>`__ (1.17 or later)
-- `pandas <http://pandas.pydata.org/>`__ (1.0 or later)
+- Python (3.8 or later)
+- `numpy <https://www.numpy.org/>`__ (1.18 or later)
+- `pandas <https://pandas.pydata.org/>`__ (1.1 or later)
 
 .. _optional-dependencies:
 
@@ -103,7 +101,7 @@ release is guaranteed to work.
 
 You can see the actual minimum tested versions:
 
-`<https://github.com/pydata/xarray/blob/main/ci/requirements/py37-min-all-deps.yml>`_
+`<https://github.com/pydata/xarray/blob/main/ci/requirements/py38-min-all-deps.yml>`_
 
 .. _installation-instructions:
 

doc/whats-new.rst

@@ -40,6 +40,8 @@ Deprecations
 ~~~~~~~~~~~~
 - Removed the lock kwarg from the zarr and pydap backends, completing the deprecation cycle started in :issue:`5256`.
   By `Tom Nicholas <https://github.com/TomNicholas>`_.
+- Support for ``python 3.7`` has been dropped. (:pull:`5892`)
+  By `Jimmy Westling <https://github.com/illviljan>`_.
 
 
 Bug fixes

requirements.txt

@@ -2,7 +2,5 @@
 # it exists to let GitHub build the repository dependency graph
 # https://help.github.com/en/github/visualizing-repository-data-with-graphs/listing-the-packages-that-a-repository-depends-on
 
-numpy >= 1.17
-pandas >= 1.0
-setuptools >= 40.4
-typing-extensions >= 3.7
+numpy >= 1.18
+pandas >= 1.1

setup.cfg

@@ -64,7 +64,6 @@ classifiers =
     Intended Audience :: Science/Research
     Programming Language :: Python
     Programming Language :: Python :: 3
-    Programming Language :: Python :: 3.7
     Programming Language :: Python :: 3.8
     Programming Language :: Python :: 3.9
     Programming Language :: Python :: 3.10
@@ -74,12 +73,10 @@ classifiers =
 packages = find:
 zip_safe = False  # https://mypy.readthedocs.io/en/latest/installed_packages.html
 include_package_data = True
-python_requires = >=3.7
+python_requires = >=3.8
 install_requires =
     numpy >= 1.18
     pandas >= 1.1
-    importlib-metadata; python_version < '3.8'
-    typing_extensions >= 3.7; python_version < '3.8'
 
 [options.extras_require]
 io =

xarray/core/dataarray.py

@@ -1,7 +1,6 @@
 from __future__ import annotations
 
 import datetime
-import sys
 import warnings
 from typing import (
     TYPE_CHECKING,
@@ -11,6 +10,7 @@
     Hashable,
     Iterable,
     List,
+    Literal,
     Mapping,
     Optional,
     Sequence,
@@ -90,12 +90,6 @@
 
     from .types import T_DataArray, T_Xarray
 
-# TODO: Remove this check once python 3.7 is not supported:
-if sys.version_info >= (3, 8):
-    from typing import Literal
-else:
-    from typing_extensions import Literal
-
 
 def _infer_coords_and_dims(
     shape, coords, dims

xarray/core/npcompat.py

@@ -28,7 +28,6 @@
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-import sys
 from typing import TYPE_CHECKING, Any, Sequence, TypeVar, Union
 
 import numpy as np
@@ -39,10 +38,7 @@
     from numpy.typing import ArrayLike, DTypeLike
 except ImportError:
     # fall back for numpy < 1.20, ArrayLike adapted from numpy.typing._array_like
-    if sys.version_info >= (3, 8):
-        from typing import Protocol
-    else:
-        from typing_extensions import Protocol
+    from typing import Protocol
 
     if TYPE_CHECKING:
 

xarray/core/options.py

@@ -1,17 +1,8 @@
-import sys
 import warnings
+from typing import TYPE_CHECKING, Literal, TypedDict, Union
 
 from .utils import FrozenDict
 
-# TODO: Remove this check once python 3.7 is not supported:
-if sys.version_info >= (3, 8):
-    from typing import TYPE_CHECKING, Literal, TypedDict, Union
-else:
-    from typing import TYPE_CHECKING, Union
-
-    from typing_extensions import Literal, TypedDict
-
-
 if TYPE_CHECKING:
     try:
         from matplotlib.colors import Colormap