Drop support for Python 3.7 (#531)

* Drop support for Python 3.7

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

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

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

.github/workflows/test.yaml

@@ -57,8 +57,6 @@ jobs:
           #   we test integration with. We can test against only one version and
           #   that would be fine.
           #
-          - python-version: "3.7"
-            go-version: "1.15"
           - python-version: "3.8"
             go-version: "1.16"
           - python-version: "3.9"

.pre-commit-config.yaml

@@ -26,7 +26,7 @@ repos:
     hooks:
       - id: pyupgrade
         args:
-          - --py37-plus
+          - --py38-plus
 
   # Autoformat: Python code
   - repo: https://github.com/psf/black

dask-gateway-server/dask_gateway_server/backends/local.py

@@ -54,7 +54,7 @@ async def wait_is_shutdown(pid, timeout=10):
     return False
 
 
-@functools.lru_cache()
+@functools.lru_cache
 def getpwnam(username):
     return pwd.getpwnam(username)
 

dask-gateway-server/setup.py

@@ -150,7 +150,6 @@ def run(self):
         "Topic :: System :: Distributed Computing",
         "Topic :: System :: Systems Administration",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
@@ -173,7 +172,7 @@ def run(self):
     package_data=package_data,
     install_requires=install_requires,
     extras_require=extras_require,
-    python_requires=">=3.7",
+    python_requires=">=3.8",
     entry_points={
         "console_scripts": [
             "dask-gateway-server = dask_gateway_server.app:main",

dask-gateway/setup.py

@@ -44,7 +44,6 @@
         "Topic :: Scientific/Engineering",
         "Topic :: System :: Distributed Computing",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
         "Programming Language :: Python :: 3.9",
         "Programming Language :: Python :: 3.10",
@@ -64,6 +63,6 @@
     package_data={"dask_gateway": ["*.yaml"]},
     install_requires=install_requires,
     extras_require=extras_require,
-    python_requires=">=3.7",
+    python_requires=">=3.8",
     zip_safe=False,
 )

pyproject.toml

@@ -1,7 +1,7 @@
 [tool.black]
 line-length = 88
 # target-version should be all supported versions
-target-version = ['py37', 'py38', 'py39', 'py310']
+target-version = ['py38', 'py39', 'py310']
 
 [tool.pytest.ini_options]
 # GitHub Actions make it hard for pytest to conclude it should use colors, due