Drop Python 2 support (#8591)

Fixes #8389 #8584.

This PR makes the necessary modifications to officially drop Python 2 support in the Certbot project.

I did not remove the specific Python 2 compatibility branches that has been added in various places in the codebase, to reduce the size of this PR and this will be done in a future one

* Update classifiers and python_requires in setup.py

* Remove warnings about Python 2 deprecation

* Remove Azure jobs on Python 2.7

* Remove references to python 2 in documentation

* Pin dnspython to 2.1.0

* Update changelog

* Remove warning ignore

.azure-pipelines/templates/jobs/extended-tests-jobs.yml

@@ -37,14 +37,6 @@ jobs:
           PYTHON_VERSION: 3.6
           TOXENV: integration-nginx-oldest
           ACME_SERVER: boulder-v2
-        linux-boulder-v1-py27-integration:
-          PYTHON_VERSION: 2.7
-          TOXENV: integration
-          ACME_SERVER: boulder-v1
-        linux-boulder-v2-py27-integration:
-          PYTHON_VERSION: 2.7
-          TOXENV: integration
-          ACME_SERVER: boulder-v2
         linux-boulder-v1-py36-integration:
           PYTHON_VERSION: 3.6
           TOXENV: integration

.azure-pipelines/templates/jobs/standard-tests-jobs.yml

@@ -4,10 +4,10 @@ jobs:
       PYTHON_VERSION: 3.9
     strategy:
       matrix:
-        macos-py27:
+        macos-py36:
           IMAGE_NAME: macOS-10.15
-          PYTHON_VERSION: 2.7
+          PYTHON_VERSION: 3.6
-          TOXENV: py27
+          TOXENV: py36
         macos-py39:
           IMAGE_NAME: macOS-10.15
           PYTHON_VERSION: 3.9
@@ -32,10 +32,6 @@ jobs:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.6
           TOXENV: '{dns,nginx}-oldest'
-        linux-py27:
-          IMAGE_NAME: ubuntu-18.04
-          PYTHON_VERSION: 2.7
-          TOXENV: py27
         linux-py36:
           IMAGE_NAME: ubuntu-18.04
           PYTHON_VERSION: 3.6
@@ -65,11 +61,11 @@ jobs:
           TOXENV: modification
         apacheconftest:
           IMAGE_NAME: ubuntu-18.04
-          PYTHON_VERSION: 2.7
+          PYTHON_VERSION: 3.6
           TOXENV: apacheconftest-with-pebble
         nginxroundtrip:
           IMAGE_NAME: ubuntu-18.04
-          PYTHON_VERSION: 2.7
+          PYTHON_VERSION: 3.6
           TOXENV: nginxroundtrip
     pool:
       vmImage: $(IMAGE_NAME)

acme/acme/__init__.py

@@ -6,7 +6,6 @@ This module is an implementation of the `ACME protocol`_.
 
 """
 import sys
-import warnings
 
 # This code exists to keep backwards compatibility with people using acme.jose
 # before it became the standalone josepy package.
@@ -20,10 +19,3 @@ for mod in list(sys.modules):
     # preserved (acme.jose.* is josepy.*)
     if mod == 'josepy' or mod.startswith('josepy.'):
         sys.modules['acme.' + mod.replace('josepy', 'jose', 1)] = sys.modules[mod]
-
-if sys.version_info[0] == 2:
-    warnings.warn(
-        "Python 2 support will be dropped in the next release of acme. "
-        "Please upgrade your Python version.",
-        PendingDeprecationWarning,
-    )  # pragma: no cover

acme/setup.py

@@ -51,14 +51,12 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-apache/setup.py

@@ -39,7 +39,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -47,8 +47,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-ci/setup.py

@@ -40,14 +40,12 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-compatibility-test/setup.py

@@ -38,14 +38,12 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 3 - Alpha',
         'Intended Audience :: Developers',
         'License :: OSI Approved :: Apache Software License',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-cloudflare/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-cloudxns/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-digitalocean/setup.py

@@ -50,7 +50,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -58,8 +58,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-dnsimple/setup.py

@@ -60,7 +60,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -68,8 +68,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-dnsmadeeasy/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-gehirn/setup.py

@@ -48,7 +48,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -56,8 +56,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-google/setup.py

@@ -52,7 +52,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -60,8 +60,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-linode/setup.py

@@ -48,7 +48,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -56,8 +56,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-luadns/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-nsone/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-ovh/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-rfc2136/certbot_dns_rfc2136/_internal/dns_rfc2136.py

@@ -1,13 +1,3 @@
-# type: ignore
-# pylint: disable=no-member
-# Many attributes of dnspython are now dynamically defined which causes both
-# mypy and pylint to error about accessing attributes they think do not exist.
-# This is the case even in up-to-date versions of mypy and pylint which as of
-# writing this are 0.790 and 2.6.0 respectively. This problem may be fixed in
-# dnspython 2.1.0. See https://github.com/rthalley/dnspython/issues/598. For
-# now, let's disable these checks. This is done at the very top of the file
-# like this because "type: ignore" must be the first line in the file to be
-# respected by mypy.
 """DNS Authenticator using RFC 2136 Dynamic Updates."""
 import logging
 

certbot-dns-rfc2136/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-route53/setup.py

@@ -49,7 +49,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -57,8 +57,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-dns-sakuracloud/setup.py

@@ -48,7 +48,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -56,8 +56,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot-nginx/setup.py

@@ -35,7 +35,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Plugins',
@@ -43,8 +43,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

certbot/CHANGELOG.md

@@ -14,6 +14,7 @@ Certbot adheres to [Semantic Versioning](https://semver.org/).
   topmost (closest to the root) certificate in the chain, instead of checking
   every certificate in the chain.
   See [#8577](https://github.com/certbot/certbot/issues/8577).
+* Support for Python 2 has been removed.
 
 ### Fixed
 

certbot/certbot/__init__.py

@@ -1,13 +1,3 @@
 """Certbot client."""
-import warnings
-import sys
-
 # version number like 1.2.3a0, must have at least 2 parts, like 1.2
 __version__ = '1.12.0.dev0'
-
-if sys.version_info[0] == 2:
-    warnings.warn(
-        "Python 2 support will be dropped in the next release of Certbot. "
-        "Please upgrade your Python version.",
-        PendingDeprecationWarning,
-    )  # pragma: no cover

certbot/certbot/_internal/main.py

@@ -5,7 +5,6 @@ from __future__ import print_function
 import functools
 import logging.handlers
 import sys
-import warnings
 
 import configobj
 import josepy as jose
@@ -1404,13 +1403,6 @@ def main(cli_args=None):
         if config.func != plugins_cmd:  # pylint: disable=comparison-with-callable
             raise
 
-    if sys.version_info[0] == 2:
-        warnings.warn(
-            "Python 2 support will be dropped in the next release of Certbot. "
-            "Please upgrade your Python version.",
-            PendingDeprecationWarning,
-        )  # pragma: no cover
-
     set_displayer(config)
 
     # Reporter

certbot/docs/contributing.rst

@@ -470,11 +470,8 @@ Mypy type annotations
 =====================
 
 Certbot uses the `mypy`_ static type checker. Python 3 natively supports official type annotations,
-which can then be tested for consistency using mypy. Python 2 doesn’t, but type annotations can
+which can then be tested for consistency using mypy. Mypy does some type checks even without type
-be `added in comments`_. Mypy does some type checks even without type annotations; we can find
+annotations; we can find bugs in Certbot even without a fully annotated codebase.
-bugs in Certbot even without a fully annotated codebase.
-
-Certbot supports both Python 2 and 3, so we’re using Python 2-style annotations.
 
 Zulip wrote a `great guide`_ to using mypy. It’s useful, but you don’t have to read the whole thing
 to start contributing to Certbot.

certbot/docs/install.rst

@@ -28,7 +28,7 @@ your system.
 System Requirements
 ===================
 
-Certbot currently requires Python 2.7 or 3.6+ running on a UNIX-like operating
+Certbot currently requires Python 3.6+ running on a UNIX-like operating
 system. By default, it requires root access in order to write to
 ``/etc/letsencrypt``, ``/var/log/letsencrypt``, ``/var/lib/letsencrypt``; to
 bind to port 80 (if you use the ``standalone`` plugin) and to read and
@@ -197,12 +197,12 @@ Optionally to install the Certbot Apache plugin, you can use:
 
 .. code-block:: shell
 
-    sudo dnf install certbot python2-certbot-apache
+    sudo dnf install certbot python3-certbot-apache
 
 **FreeBSD**
 
   * Port: ``cd /usr/ports/security/py-certbot && make install clean``
-  * Package: ``pkg install py27-certbot``
+  * Package: ``pkg install py37-certbot``
 
 **Gentoo**
 
@@ -223,7 +223,7 @@ They need to be installed separately if you require their functionality.
 **NetBSD**
 
   * Build from source: ``cd /usr/pkgsrc/security/py-certbot && make install clean``
-  * Install pre-compiled package: ``pkg_add py27-certbot``
+  * Install pre-compiled package: ``pkg_add py37-certbot``
 
 **OpenBSD**
 

certbot/setup.py

@@ -116,7 +116,7 @@ setup(
     author="Certbot Project",
     author_email='client-dev@letsencrypt.org',
     license='Apache License 2.0',
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*, !=3.5.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Console',
@@ -125,8 +125,6 @@ setup(
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: POSIX :: Linux',
         'Programming Language :: Python',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',

pytest.ini

@@ -4,8 +4,6 @@
 [pytest]
 # In general, all warnings are treated as errors. Here are the exceptions:
 #   1- decodestring: https://github.com/rthalley/dnspython/issues/338
-#   2- Python 2 deprecation: https://github.com/certbot/certbot/issues/8388
-#      (to be removed with Certbot 1.12.0 and its drop of Python 2 support)
 # Warnings being triggered by our plugins using deprecated features in
 # acme/certbot should be fixed by having our plugins no longer using the
 # deprecated code rather than adding them to the list of ignored warnings here.
@@ -16,4 +14,3 @@
 filterwarnings =
     error
     ignore:decodestring:DeprecationWarning
-    ignore:Python 2 support will be dropped:PendingDeprecationWarning

tools/dev_constraints.txt

@@ -26,13 +26,7 @@ coverage==4.5.4
 decorator==4.4.1
 deprecated==1.2.10
 dns-lexicon==3.3.17
-# There is no version of dnspython that works on both Python 2 and Python 3.9.
+dnspython==2.1.0
-# To work around this, we make use of the fact that subject to other
-# constraints, pip will install the newest version of a package while ignoring
-# versions that don't support the version of Python being used. The result of
-# this is dnspython 2.0.0 is installed in Python 3 while dnspython 1.16.0 is
-# installed in Python 2.
-dnspython<=2.0.0
 docker==4.3.1
 docker-compose==1.26.2
 docker-pycreds==0.4.0