Drop Python 3.5 and test against 3.9 (marshmallow-code#125)

* Drop Python 3.5 and test against 3.9

* tox -e lint

.pre-commit-config.yaml

@@ -3,7 +3,7 @@ repos:
   rev: v2.7.2
   hooks:
   - id: pyupgrade
-    args: [--py3-plus]
+    args: [--py36-plus]
 - repo: https://github.com/python/black
   rev: 20.8b1
   hooks:

CHANGELOG.rst

@@ -1,6 +1,11 @@
 Changelog
 ---------
 
+3.0.0 (unreleased)
+++++++++++++++++++
+
+- Only support Python>=3.6 and marshmallow>=3.0.0.
+
 2.1.0 (2020-10-05)
 ++++++++++++++++++
 

azure-pipelines.yml

@@ -15,11 +15,11 @@ resources:
 jobs:
 - template: job--python-tox.yml@sloria
   parameters:
-    toxenvs: [lint, py35, py36, py37, py38, check-build]
+    toxenvs: [lint, py36, py37, py38, py39, check-build]
     os: linux
 - template: job--pypi-release.yml@sloria
   parameters:
-    python: "3.8"
+    python: "3.9"
     distributions: "sdist bdist_wheel"
     dependsOn:
       - tox_linux

setup.py

@@ -37,16 +37,16 @@ def read(fname):
         "demultiplexing",
         "polymorphic",
     ],
-    python_requires=">=3.5",
-    install_requires=["marshmallow>=3.0.0rc6,<4.0.0"],
+    python_requires=">=3.6",
+    install_requires=["marshmallow>=3.0.0,<4.0.0"],
     extras_require=EXTRAS_REQUIRE,
     classifiers=[
         "Intended Audience :: Developers",
         "License :: OSI Approved :: MIT License",
         "Programming Language :: Python :: 3",
-        "Programming Language :: Python :: 3.5",
         "Programming Language :: Python :: 3.6",
         "Programming Language :: Python :: 3.7",
         "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
     ],
 )

tests/test_one_of_schema.py

@@ -51,7 +51,7 @@ def __init__(self, value1=None, value2=None):
         self.value2 = value2
 
     def __repr__(self):
-        return "<Bar value1={} value2={}>".format(self.value1, self.value2)
+        return f"<Bar value1={self.value1} value2={self.value2}>"
 
     def __eq__(self, other):
         return (

tox.ini

@@ -2,7 +2,7 @@
 envlist=
     lint
     check-build
-    py{35,36,37,38}
+    py{36,37,38,39}
 
 [testenv]
 extras = tests