nep29: drop py37 support

.cirrus.yml

@@ -141,8 +141,6 @@ task:
   only_if: ${SKIP_TEST_TASK} == ""
   << : *CREDITS_TEMPLATE
   matrix:
-    env:
-      PY_VER: 3.7
     env:
       PY_VER: 3.8
   name: "${CIRRUS_OS}: py${PY_VER} tests"

.github/workflows/refresh-lockfiles.yml

@@ -71,7 +71,7 @@ jobs:
 
     strategy:
       matrix:
-        python: ['37', '38']
+        python: ['38']
 
     steps:
       - uses: actions/checkout@v2

docs/src/whatsnew/latest.rst

@@ -18,6 +18,7 @@ This document explains the changes made to Iris for this release
 
    * We've added experimental support for `UGRID`_ meshes which can now be loaded
      and attached to a cube.
+   * We've also dropped support for ``Python 3.7``.
 
    And finally, get in touch with us on `GitHub`_ if you have any issues or
    feature requests for improving Iris. Enjoy!
@@ -179,6 +180,9 @@ This document explains the changes made to Iris for this release
 #. `@bjlittle`_ introduced the ``numpy >=1.19`` minimum pin, in
    accordance with `NEP-29`_ deprecation policy. (:pull:`4386`)
 
+#. `@bjlittle`_ dropped support for ``Python 3.7``, as per the `NEP-29`_
+   backwards compatibility and deprecation policy schedule. (:pull:`4481`)
+
 
 📚 Documentation
 ================

noxfile.py

@@ -16,7 +16,7 @@
 nox.options.reuse_existing_virtualenvs = True
 
 #: Python versions we can run sessions under
-_PY_VERSIONS_ALL = ["3.7", "3.8"]
+_PY_VERSIONS_ALL = ["3.8"]
 _PY_VERSION_LATEST = _PY_VERSIONS_ALL[-1]
 
 #: One specific python version for docs builds

pyproject.toml

@@ -10,7 +10,7 @@ build-backend = "setuptools.build_meta"
 
 [tool.black]
 line-length = 79
-target-version = ['py37', 'py38']
+target-version = ['py38']
 include = '\.pyi?$'
 extend-exclude = '''
 (

setup.cfg

@@ -59,7 +59,7 @@ packages = find:
 package_dir =
     =lib
 python_requires =
-    >=3.7
+    >=3.8
 zip_safe = False
 
 [options.packages.find]