diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 99781ca7..cf755194 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -35,19 +35,9 @@ jobs:
         if [[ "${{ github.event_name }}" == "schedule" || "${{ github.head_ref }}" =~ ^release_ ]]; then \
           echo "matrix={ \
             \"os\": [ \"ubuntu-latest\", \"macos-latest\", \"windows-latest\" ], \
-            \"python-version\": [ \"3.5\", \"3.6\", \"3.7\", \"3.8\", \"3.9\", \"3.10\", \"3.11\" ], \
+            \"python-version\": [ \"3.6\", \"3.7\", \"3.8\", \"3.9\", \"3.10\", \"3.11\" ], \
             \"package_level\": [ \"minimum\", \"latest\" ], \
             \"exclude\": [ \
-              { \
-                \"os\": \"ubuntu-latest\", \
-                \"python-version\": \"3.5\", \
-                \"package_level\": \"minimum\" \
-              }, \
-              { \
-                \"os\": \"ubuntu-latest\", \
-                \"python-version\": \"3.5\", \
-                \"package_level\": \"latest\" \
-              }, \
               { \
                 \"os\": \"ubuntu-latest\", \
                 \"python-version\": \"3.6\", \
@@ -60,28 +50,6 @@ jobs:
               } \
             ], \
             \"include\": [ \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"2.7\", \
-                \"package_level\": \"minimum\", \
-                \"container\": {\"image\": \"python:2.7.18-buster\"} \
-              }, \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"2.7\", \
-                \"package_level\": \"latest\", \
-                \"container\": {\"image\": \"python:2.7.18-buster\"} \
-              }, \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"3.5\", \
-                \"package_level\": \"minimum\" \
-              }, \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"3.5\", \
-                \"package_level\": \"latest\" \
-              }, \
               { \
                 \"os\": \"ubuntu-20.04\", \
                 \"python-version\": \"3.6\", \
@@ -100,28 +68,6 @@ jobs:
             \"python-version\": [ \"3.11\" ], \
             \"package_level\": [ \"minimum\", \"latest\" ], \
             \"include\": [ \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"2.7\", \
-                \"package_level\": \"minimum\", \
-                \"container\": {\"image\": \"python:2.7.18-buster\"} \
-              }, \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"2.7\", \
-                \"package_level\": \"latest\", \
-                \"container\": {\"image\": \"python:2.7.18-buster\"} \
-              }, \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"3.5\", \
-                \"package_level\": \"minimum\" \
-              }, \
-              { \
-                \"os\": \"ubuntu-20.04\", \
-                \"python-version\": \"3.5\", \
-                \"package_level\": \"latest\" \
-              }, \
               { \
                 \"os\": \"ubuntu-20.04\", \
                 \"python-version\": \"3.6\", \
@@ -129,7 +75,7 @@ jobs:
               }, \
               { \
                 \"os\": \"macos-latest\", \
-                \"python-version\": \"3.5\", \
+                \"python-version\": \"3.6\", \
                 \"package_level\": \"latest\" \
               }, \
               { \
@@ -139,7 +85,7 @@ jobs:
               }, \
               { \
                 \"os\": \"windows-latest\", \
-                \"python-version\": \"3.5\", \
+                \"python-version\": \"3.6\", \
                 \"package_level\": \"latest\" \
               }, \
               { \
@@ -175,7 +121,6 @@ jobs:
       with:
         fetch-depth: 0
     - name: Set up Python ${{ matrix.python-version }}
-      if: ${{ ! ( matrix.python-version == '2.7' ) }}
       uses: actions/setup-python@v4
       with:
         python-version: ${{ matrix.python-version }}
diff --git a/.pylintrc b/.pylintrc
index dcf181e6..5f070f5b 100644
--- a/.pylintrc
+++ b/.pylintrc
@@ -67,7 +67,6 @@ ignore-patterns=^\.#
 #       on the module ignore list. For details, see
 #       https://bitbucket.org/logilab/pylint/issues/223/ignored-modules-should-turn-no-name-in
 ignored-modules=distutils,
-                six,
                 builtins,
                 urllib,
                 lxml,
@@ -347,7 +346,7 @@ init-import=no
 
 # List of qualified module names which can have objects that can redefine
 # builtins.
-redefining-builtins-modules=six.moves,past.builtins,future.builtins,builtins,io
+redefining-builtins-modules=past.builtins,future.builtins,builtins,io
 
 
 [FORMAT]
diff --git a/.safety-policy.yml b/.safety-policy.yml
index 330b1a90..893bf38d 100644
--- a/.safety-policy.yml
+++ b/.safety-policy.yml
@@ -20,38 +20,16 @@ security:
     #     reason: {text}    # optional: Reason for ignoring it. Will be reported in the Safety reports
     #     expires: {date}   # optional: Date when this ignore will expire
     ignore-vulnerabilities:
-        37504:
-            reason: Fixed Twine version requires Python>=3.6 and is used there
-        38330:
-            reason: Fixed Sphinx version requires Python>=3.5 and is used there
         39611:
-            reason: PyYAML full_load method or FullLoader is not used
-        39621:
-            reason: Fixed Pylint version requires Python>=3.6 and is used there
-        40291:
-            reason: Fixed Pip version requires Python>=3.6 and is used there
-        42559:
-            reason: Fixed Pip version requires Python>=3.6 and is used there; Pip is not shipped with this package
+            reason: Fixed PyYAML versions 5.4 to 6.0.0 do not work with Cython 3, and the full_load method or FullLoader is not used
         43975:
             reason: Fixed Urllib3 versions are excluded by requests
-        45185:
-            reason: Fixed Pylint version requires Python>=3.6.2 and is used there
-        45775:
-            reason: Fixed Sphinx version requires Python>=3.5 and is used there
-        47833:
-            reason: Fixed Click version requires Python>=3.6 and is used there
-        50885:
-            reason: Fixed Pygments version requires Python>=3.5 and is used there
-        50886:
-            reason: Fixed Pygments version requires Python>=3.5 and is used there
         51457:
             reason: Py package will no longer be fixed (latest version 1.11.0)
         51499:
             reason: Fixed Wheel version requires Python>=3.7 and is used there; Risk is on Pypi side
         52322:
             reason: Fixed GitPython version requires Python>=3.7 and is used there
-        52365:
-            reason: Fixed Certifi version requires Python>=3.6 and is used there
         52495:
             reason: Fixed Setuptools version requires Python>=3.7 and is used there; Risk is on Pypi side
         52518:
@@ -60,12 +38,6 @@ security:
             reason: Fixed requests version 2.31.0 requires Python>=3.7 and is used there
         58910:
             reason: Fixed pygments version 2.15.0 requires Python>=3.7 and is used there
-        59956:
-            reason: Fixed certifi version 2023.07.22 requires Python>=3.6 and is used there
-        59910:
-            reason: Fixed sphinx version 3.3.0 requires Python>=3.5 and is used there
-        59925:
-            reason: Fixed sphinx version 3.3.0 requires Python>=3.5 and is used there
         60350:
             reason: Fixed GitPython version 3.1.32 requires Python>=3.7 and is used there
         60789:
diff --git a/Makefile b/Makefile
index 59215e07..f6df0069 100644
--- a/Makefile
+++ b/Makefile
@@ -5,20 +5,20 @@
 #   One of these OS platforms:
 #     Windows with CygWin
 #     Linux (any)
-#     OS-X
+#     macOS (OS-X)
 #   These commands on all OS platforms:
 #     make (GNU make)
 #     bash
 #     rm, mv, find, tee, which
 #   These commands on all OS platforms in the active Python environment:
-#     python (or python3 on OS-X)
-#     pip (or pip3 on OS-X)
+#     python
+#     pip
 #     twine
-#   These commands on Linux and OS-X:
+#   These commands on Linux and macOS:
 #     uname
 # Environment variables:
-#   PYTHON_CMD: Python command to use (OS-X needs to distinguish Python 2/3)
-#   PIP_CMD: Pip command to use (OS-X needs to distinguish Python 2/3)
+#   PYTHON_CMD: Python command to use
+#   PIP_CMD: Pip command to use
 #   PACKAGE_LEVEL: minimum/latest - Level of Python dependent packages to use
 # Additional prerequisites for running this Makefile are installed by running:
 #   make develop
@@ -110,8 +110,6 @@ package_version := $(shell $(PYTHON_CMD) setup.py --version)
 # Python versions
 python_version := $(shell $(PYTHON_CMD) -c "import sys; sys.stdout.write('{v[0]}.{v[1]}.{v[2]}'.format(v=sys.version_info))")
 pymn := $(shell $(PYTHON_CMD) -c "import sys; sys.stdout.write('py{v[0]}{v[1]}'.format(v=sys.version_info))")
-python_m_version := $(shell $(PYTHON_CMD) -c "import sys; sys.stdout.write('{v[0]}'.format(v=sys.version_info))")
-python_mn_version := $(shell $(PYTHON_CMD) -c "import sys; sys.stdout.write('{v[0]}.{v[1]}'.format(v=sys.version_info))")
 
 # Directory for the generated distribution files
 dist_dir := dist
@@ -441,30 +439,18 @@ $(bdist_file) $(sdist_file): _check_version Makefile MANIFEST.in $(dist_included
 
 # TODO: Once PyLint has no more errors, remove the dash "-"
 pylint_$(pymn)_$(PACKAGE_LEVEL).done: develop_$(pymn)_$(PACKAGE_LEVEL).done Makefile $(pylint_rc_file) $(check_py_files)
-ifeq ($(python_m_version),2)
-	@echo "Makefile: Warning: Skipping Pylint on Python $(python_version)" >&2
-else
 	@echo "Makefile: Running Pylint"
 	-$(call RM_FUNC,$@)
 	pylint $(pylint_opts) --rcfile=$(pylint_rc_file) --output-format=text $(check_py_files)
 	echo "done" >$@
 	@echo "Makefile: Done running Pylint"
-endif
 
 safety_$(pymn)_$(PACKAGE_LEVEL).done: develop_$(pymn)_$(PACKAGE_LEVEL).done Makefile $(safety_policy_file) minimum-constraints.txt
-ifeq ($(python_m_version),2)
-	@echo "Makefile: Warning: Skipping Safety on Python $(python_version)" >&2
-else
-ifeq ($(python_mn_version),3.5)
-	@echo "Makefile: Warning: Skipping Safety on Python $(python_version)" >&2
-else
 	@echo "Makefile: Running Safety"
 	-$(call RM_FUNC,$@)
 	safety check --policy-file $(safety_policy_file) -r minimum-constraints.txt --full-report
 	echo "done" >$@
 	@echo "Makefile: Done running Safety"
-endif
-endif
 
 flake8_$(pymn)_$(PACKAGE_LEVEL).done: develop_$(pymn)_$(PACKAGE_LEVEL).done Makefile $(flake8_rc_file) $(check_py_files)
 	-$(call RM_FUNC,$@)
@@ -473,9 +459,6 @@ flake8_$(pymn)_$(PACKAGE_LEVEL).done: develop_$(pymn)_$(PACKAGE_LEVEL).done Make
 
 .PHONY: check_reqs
 check_reqs: develop_$(pymn)_$(PACKAGE_LEVEL).done minimum-constraints.txt requirements.txt
-ifeq ($(python_m_version),2)
-	@echo "Makefile: Warning: Skipping the checking of missing dependencies on Python $(python_version)" >&2
-else
 	@echo "Makefile: Checking missing dependencies of this package"
 	pip-missing-reqs $(package_name) --requirements-file=requirements.txt
 	pip-missing-reqs $(package_name) --requirements-file=minimum-constraints.txt
@@ -487,7 +470,6 @@ else
 	@echo "Makefile: Checking missing dependencies of some development packages in our minimum versions"
 	@rc=0; for pkg in $(check_reqs_packages); do dir=$$($(PYTHON_CMD) -c "import $${pkg} as m,os; dm=os.path.dirname(m.__file__); d=dm if not dm.endswith('site-packages') else m.__file__; print(d)"); cmd="pip-missing-reqs $${dir} --requirements-file=minimum-constraints.txt"; echo $${cmd}; $${cmd}; rc=$$(expr $${rc} + $${?}); done; exit $${rc}
 	@echo "Makefile: Done checking missing dependencies of some development packages in our minimum versions"
-endif
 endif
 	@echo "Makefile: $@ done."
 
diff --git a/base-requirements.txt b/base-requirements.txt
index 624f3eef..5b282c7b 100644
--- a/base-requirements.txt
+++ b/base-requirements.txt
@@ -9,12 +9,11 @@
 
 # Base dependencies (must be consistent with minimum-constraints.txt)
 
-pip>=10.0.1; python_version <= '3.5'
-pip>=21.2.4; python_version >= '3.6'
-setuptools>=39.0.1; python_version <= '3.6'
+pip>=21.2.4
+setuptools>=39.0.1; python_version == '3.6'
 setuptools>=40.6.0; python_version == '3.7'
 setuptools>=41.5.0; python_version >= '3.8' and python_version <= '3.9'
 setuptools>=49.0.0; python_version >= '3.10'
-wheel>=0.30.0; python_version <= '3.6'
+wheel>=0.30.0; python_version == '3.6'
 wheel>=0.32.0; python_version == '3.7'
 wheel>=0.33.5; python_version >= '3.8'
diff --git a/dev-requirements.txt b/dev-requirements.txt
index fe468fb5..92b8468b 100644
--- a/dev-requirements.txt
+++ b/dev-requirements.txt
@@ -11,13 +11,20 @@
 # Runtime dependencies:
 -r requirements.txt
 
+# six
+# tox 3.17 requires six>=1.14.0 (tox 4.0 no longer uses six)
+# zhmcclient 1.11 requires six>=1.14.0 up to py39 and six>=1.16.0 from py310 on
+# python-dateutil 2.8 requires six>=1.5
+# sphinx-git 11.0 requires six (any version)
+# coverage imports six when testing, but does not declare it in its dependencies. check_reqs still needs it.
+six>=1.14.0; python_version <= '3.9'
+six>=1.16.0; python_version >= '3.10'
 
 # Tox
 tox>=2.5.0
 
 # Virtualenv
 # build requires virtualenv.cli_run which was added in 20.1
-# virtualenv 20.0 requires six<2,>=1.12.0
 virtualenv>=20.1.0
 
 # PEP517 package builder, used in Makefile
@@ -26,132 +33,87 @@ build>=0.5.0
 pep517>=0.9.1
 
 # Safety CI by pyup.io
-# Safety is run only on Python >=3.6
-safety>=2.2.0; python_version >= '3.6'
-dparse>=0.6.2; python_version >= '3.6'
+safety>=2.2.0
+dparse>=0.6.2
 
 # Unit test:
-# pytest 5.0.0 has removed support for Python < 3.5
 # pytest 4.3.1 solves an issue on Python 3 with minimum package levels
-pytest>=4.6.11,<5.0.0; python_version == '2.7'
-pytest>=4.6.11; python_version >= '3.5' and python_version <= '3.9'
+pytest>=4.6.11; python_version <= '3.9'
 pytest>=6.2.5; python_version >= '3.10'
 # flake8 up to 6.0.0 has not yet adjusted to the removed interfaces of importlib-metadata 5.0
-importlib-metadata>=0.22,<4.3; python_version <= '3.6'
+importlib-metadata>=0.22,<4.3; python_version == '3.6'
 importlib-metadata>=1.1.0,<4.3; python_version >= '3.7'
 
 # packaging is used by pytest, pip-check-reqs, sphinx
 # packaging>=20.5 is needed by pip-check-reqs 2.4.3 but it requires only packaging>=16.0
-# packaging 21.0 removed support for Python <3.6
 # packaging 22.0 removed support for py36
-packaging>=20.5; python_version <= '3.5'
-packaging>=21.0,<22.0; python_version >= '3.6'
+packaging>=21.0,<22.0
 
-# colorama 0.4.3 has removed support for Python < 3.5
-colorama>=0.3.9; python_version == '2.7'
-colorama>=0.4.5; python_version >= '3.5'
+colorama>=0.4.5
 
 # Coverage reporting (no imports, invoked via coveralls script):
 coverage>=5.5
 pytest-cov>=2.12.1
-# coveralls 2.0 has removed support for Python 2.7
-git+https://github.com/andy-maier/coveralls-python.git@andy/add-py27#egg=coveralls; python_version == '2.7'
-coveralls>=3.3.0; python_version >= '3.5'
-
-# PyYAML: covered in direct deps for development
+coveralls>=3.3.0
 
 # Sphinx (no imports, invoked via sphinx-build script):
-# Sphinx 2.0.0 removed support for Python 2.7
 # Sphinx 4.0.0 breaks autodocsumm and needs to be excluded
 # Sphinx <4.3.0 requires docutils <0.18 due to an incompatibility
-# Sphinx 3.0.4 fixes safety issues 45775,38330
 # Sphinx <4.2.0 fails on Python 3.10 because it tries to import non-existing
 #   types.Union. This also drives docutils>=0.14.
-# Sphinx pins docutils to <0.18 (some versions even to <0.17) but the package
-#   version resolver in the pip version used on py27 ignores package dependencies
-Sphinx>=1.7.6,<2.0.0; python_version == '2.7'
-Sphinx>=3.5.4,!=4.0.0,<4.3.0; python_version >= '3.5' and python_version <= '3.9'
+Sphinx>=3.5.4,!=4.0.0,<4.3.0; python_version <= '3.9'
 Sphinx>=4.2.0; python_version >= '3.10'
-docutils>=0.13.1,<0.17; python_version == '2.7'
-docutils>=0.13.1,<0.17; python_version >= '3.5' and python_version <= '3.9'
+docutils>=0.13.1,<0.17; python_version <= '3.9'
 docutils>=0.14,<0.17; python_version == '3.10'
 docutils>=0.16,<0.17; python_version >= '3.11'
 sphinx-git>=10.1.1
-# GitPython version 3.0.0 and newer does not support Python 2.7
 # GitPython version 3.1.24 requires Python >=3.7
-# GitPython version 3.1.27 fixes safety issue #52518
-# GitPython 3.1.30 fixes safety issues 52322,52518
-GitPython>=2.1.1,<3.0.0; python_version == '2.7'
-GitPython>=2.1.1; python_version >= '3.5' and python_version <= '3.6'
+GitPython>=2.1.1; python_version == '3.6'
 GitPython>=3.1.37; python_version >= '3.7'
-# Pygments 2.7.4 fixes safety issues 50885,50886
-Pygments>=2.4.1; python_version == '2.7'
-Pygments>=2.7.4; python_version >= '3.5' and python_version <= '3.6'
+Pygments>=2.7.4; python_version == '3.6'
 Pygments>=2.15.0; python_version >= '3.7'
 sphinx-rtd-theme>=1.0.0
-# Babel 2.7.0 fixes an ImportError for MutableMapping which starts failing on Python 3.10
-# Babel 2.9.1 fixes safety issue 42203
 Babel>=2.9.1
 
 # PyLint (no imports, invoked via pylint script)
-# Pylint is not run on py27 anymore
 # Pylint requires astroid
-# Pylint 1.x / astroid 1.x supports py27 and py34/35/36
-# Pylint 2.0 / astroid 2.0 removed py27, added py37
-# Pylint 2.4 / astroid 2.3 removed py34
-# Issue #2673: Pinning Pylint to <2.7.0 is a circumvention for Pylint issue
-#   https://github.com/PyCQA/pylint/issues/4120 that appears in Pylint 2.7.0.
-#   Pylint 2.10 has fixed the issue.
-# Pylint 2.7.0 fixes safety issue 39621
-# Pylint 2.13.0 fixes safety issue 45185
-pylint>=2.5.2,<2.7.0; python_version == '3.5'
 pylint>=2.13.0,<2.14.0; python_version == '3.6'
 pylint>=2.13.0; python_version >= '3.7' and python_version <= '3.10'
 pylint>=2.15.0; python_version >= '3.11'
-astroid>=2.4.0,<2.6.0; python_version == '3.5'
-astroid>=2.11.0; python_version >= '3.6' and python_version <= '3.10'
+astroid>=2.11.0; python_version <= '3.10'
 astroid>=2.12.4; python_version >= '3.11'
-typed-ast>=1.4.0,<1.5.0; python_version >= '3.6' and python_version < '3.8' and implementation_name=='cpython'
+typed-ast>=1.4.0,<1.5.0; python_version <= '3.7' and implementation_name=='cpython'
 # lazy-object-proxy is used by astroid
-lazy-object-proxy>=1.4.3; python_version >= '3.5'
-wrapt>=1.11.2; python_version >= '3.5' and python_version <= '3.10'
+lazy-object-proxy>=1.4.3
+wrapt>=1.11.2; python_version <= '3.10'
 wrapt>=1.14; python_version >= '3.11'
 # platformdirs is used by pylint starting with its 2.10
-platformdirs>=2.2.0; python_version >= '3.6'
-# isort 5.0.0 removed support for py27,py35
+platformdirs>=2.2.0
 # isort 4.2.8 fixes a pylint issue with false positive on import order of ssl on Windows
 # isort 4.3.8 fixes an issue with py310 and works on py310 (Note that isort 5.10.0 has official support for py310)
 isort>=4.3.8
 # Pylint 2.14 uses tomlkit>=0.10.1 and requires py>=3.7
 tomlkit>=0.10.1; python_version >= '3.7'
 # dill is used by pylint >=2.13
-dill>=0.2; python_version >= '3.6' and python_version <= '3.10'
+dill>=0.2; python_version <= '3.10'
 dill>=0.3.6; python_version >= '3.11'
 
 # Flake8 and dependents (no imports, invoked via flake8 script):
-# flake8 3.9.0 has removed support for py34 and pip 19.1.1 on py34 does not deal
-# well with its pinned dependencies, so we need to repeat these for py34.
 # flake8 4.0.0 fixes an AttributeError on Python 3.10.
 flake8>=3.8.0; python_version <= '3.9'
 flake8>=4.0.0; python_version >= '3.10'
 mccabe>=0.6.0
-pycodestyle>=2.6.0,<2.8.0; python_version == '2.7'
-pycodestyle>=2.6.0; python_version >= '3.5' and python_version <= '3.9'
+pycodestyle>=2.6.0; python_version <= '3.9'
 pycodestyle>=2.8.0; python_version >= '3.10'
-pyflakes>=2.2.0,<2.4.0; python_version == '2.7'
-pyflakes>=2.2.0; python_version >= '3.5' and python_version <= '3.9'
+pyflakes>=2.2.0; python_version <= '3.9'
 pyflakes>=2.4.0; python_version >= '3.10'
 entrypoints>=0.3.0
-functools32>=3.2.3.post2; python_version == '2.7'  # technically: python_version < '3.2'
 
 # Twine (no imports, invoked via twine script):
-# twine 2.0.0 removed support for Python < 3.6
-twine>=1.8.1,<2.0.0; python_version <= '3.5'
-twine>=3.0.0; python_version >= '3.6'
+twine>=3.0.0
 # readme-renderer 23.0 has made cmarkgfm part of extras (it fails on Cygwin)
 # readme-renderer 25.0 or higher is needed to address issue on Windows with py39
-readme-renderer>=23.0; python_version == '2.7'
-readme-renderer>=25.0; python_version >= '3.5'
+readme-renderer>=25.0
 
 # Unit test (indirect dependencies):
 # Pluggy 0.12.0 has a bug causing pytest plugins to fail loading on py38
@@ -159,49 +121,9 @@ pluggy>=0.13.1
 
 # Package dependency management tools (not used by any make rules)
 pipdeptree>=2.2.0
-# pip-check-reqs is not used on Python 2.7
 # pip-check-reqs 2.3.2 is needed to have proper support for pip<21.3.
 # pip-check-reqs 2.4.0 requires Python>=3.8.
 # pip-check-reqs 2.4.3 fixes a speed issue on Python 3.11 and requires pip>=21.2.4
 # pip-check-reqs 2.5.0 has issue https://github.com/r1chardj0n3s/pip-check-reqs/issues/143
-pip-check-reqs>=2.3.2; python_version >= '3.5' and python_version <= '3.7'
+pip-check-reqs>=2.3.2; python_version <= '3.7'
 pip-check-reqs>=2.4.3,!=2.5.0; python_version >= '3.8'
-
-# Indirect dependencies (normally commented out, only listed to document their license):
-
-# alabaster # BSD, from Sphinx
-# atomicwrites # TBD
-# attrs # TBD
-# backports.functools-lru-cache # MIT, from pylint
-# bleach # Apache, from ???
-# configparser # MIT, from pylint and from flake8 for py<3.2
-# contextlib2 # TBD
-# coverage # Apache-2.0, from pytest-cov
-# docutils # public domain | Python | 2-Clause BSD | GPL 3, from Sphinx
-# enum34 # BSD, from astroid
-# funcsigs # Apache, from mock for py<3.3
-# futures # TBD
-# gitdb2 # BSD, from GitPython
-# gitdb # BSD, from GitPython
-# imagesize # MIT, from Sphinx
-# isort # MIT, from pylint
-# Jinja2 # BSD, from Sphinx
-# keyring # TBD
-# MarkupSafe # BSD, from Jinja2 -> Sphinx
-# more-itertools # TBD
-# packaging # TBD
-# pathlib2 # MIT, from ???
-# pkginfo # MIT, from twine
-# py # MIT, from pytest
-# pyparsing # TBD
-# requests-toolbelt # Apache 2.0, from twine
-# scandir # New BSD, from pathlib2 for py<3.6 -> pytest
-# singledispatch # MIT, from pylint
-# smmap2 # BSD, from gitdb2 -> GitPython
-# smmap # BSD, from gitdb -> GitPython
-# snowballstemmer # BSD, from Sphinx
-# sphinxcontrib-websupport # BSD, from Sphinx>=1.6.1
-# tqdm # MPL 2.0, MIT, from twine>=1.9.1
-# typing # PSFL, from Sphinx>=1.6.1 for py<3.5
-# webencodings # BSD, from ???
-# zipp # TBD
diff --git a/docs/changes.rst b/docs/changes.rst
index 498e1301..3a936779 100644
--- a/docs/changes.rst
+++ b/docs/changes.rst
@@ -29,6 +29,13 @@ Released: not yet
 
 **Incompatible changes:**
 
+* Dropped support for Python 2.7 and 3.5. These Python versions went out
+  of support by the PSF in 2020. If you still use these Python versions
+  today, you should seriously consider upgrading to a supported Python
+  version.
+  As far as the zhmccli package goes, you can still use versions up to
+  1.9.x on Python 2.7 and 3.5.
+
 **Deprecations:**
 
 **Bug fixes:**
diff --git a/docs/intro.rst b/docs/intro.rst
index 65a958c5..9971f2f6 100644
--- a/docs/intro.rst
+++ b/docs/intro.rst
@@ -47,7 +47,7 @@ The zhmccli package is supported in these environments:
 
 * Operating systems: Linux, Windows, OS-X
 
-* Python versions: 2.7, 3.5, and higher 3.x
+* Python versions: 3.6 and higher
 
 * HMC versions: 2.11.1 and higher
 
diff --git a/minimum-constraints.txt b/minimum-constraints.txt
index 2a8691ba..d3691c67 100644
--- a/minimum-constraints.txt
+++ b/minimum-constraints.txt
@@ -15,69 +15,8 @@
 # the minimum versions required in requirements.txt and dev-requirements.txt.
 
 
-# Dependencies for installation with Pip (must be installed in a separate pip call)
-#
-# Info: OS-installed package versions for some Linux distros:
-# * RHEL/CentOS 7.4.1708:
-#   Python      2.7.5     2013-05-15
-#   pip         8.1.2     2016-05-11 (epel)
-#   setuptools  0.9.8     2013-07-25
-#   wheel       0.24.0    2014-07-06 (epel)
-#   pbr         1.8.1     2015-10-07 (epel)
-# * Ubuntu 16.04.03:
-#   Python      2.7.12    2016-11-19
-#   pip         8.1.1     2016-03-17
-#   setuptools  20.7.0    2016-04-10
-#   wheel       0.29.0    2016-02-06
-#   pbr         1.8.0     2015-09-14
-# * Ubuntu 17.04:
-#   Python      2.7.12    2016-11-19
-#   pip         9.0.1     2016-11-06
-#   setuptools  33.1.1    2017-01-16
-#   wheel       0.29.0    2016-02-06
-#   pbr         1.10.0    2016-05-23
-# * Ubuntu 18.04:
-#   Python      2.7.15
-#   Python3     3.6.5
-#   pip         9.0.1     (py2+py3)
-#   setuptools  39.0.1    (py2+py3)
-#   wheel       0.30.0    (py2+py3)
-# * Ubuntu 19.04:
-#   Python      2.7.16
-#   Python3     3.7.3
-#   pip         18.1      (py2+py3)
-#   setuptools  40.8.0    (py2+py3)
-#   wheel       0.32.3    (py2+py3)
-
-
 # Base dependencies (must be consistent with base-requirements.txt)
 
-# Info: Python version supported by base packages (added / removed)
-# * Python 2.7 support:
-#   pip         ?
-#   setuptools  ? / 45.0.0
-#   wheel       ?
-# * Python 3.4 support:
-#   pip         ? / 19.2
-#   setuptools  ? / 44.0.0
-#   wheel       ? / 0.34.0
-# * Python 3.5 support:
-#   pip         8.0
-#   setuptools  18.3
-#   wheel       0.30.0
-# * Python 3.6 support:
-#   pip         10.0.0
-#   setuptools  34.0.0
-#   wheel       0.30.0
-# * Python 3.7 support:
-#   pip         18.1
-#   setuptools  40.6.0
-#   wheel       0.32.0
-# * Python 3.8 support:
-#   pip         19.3.1
-#   setuptools  41.5.0
-#   wheel       0.33.5
-
 # For the base packages, we use the versions from Ubuntu 18.04 as a general
 # minimum, and then increase it to the first version that introduced support
 # for a particular Python version:
@@ -85,22 +24,13 @@
 # pip 18.0 is needed on pypy3 (py36) to support constraints like cffi!=1.11.3,>=1.8.
 # pip 18.1 supports PEP-508 URLs, so the deprecated dependency_links no longer needs to be used.
 # Pip 20.2 introduced a new resolver whose backtracking had issues that were resolved only in 21.2.2.
-# Pip 21.0 removed support for Python<=3.5
 # pip>=21.0 is needed for the cryptography package on Windows on GitHub Actions.
-# pip 19.2 fixes safety issue 38765
-# pip 21.1 fixes safety issues 42559,40291
-pip==19.3.1; python_version <= '3.5'
 pip==21.2.4; python_version >= '3.6' and python_version <= '3.9'
 pip==23.0.1; python_version >= '3.10'
-# setuptools 51.0.0 removed support for py35
 # setuptools 59.7.0 removed support for py36
-# setuptools 65.5.1 fixes safety issue 52495
-setuptools==39.0.1; python_version == '2.7'
-setuptools==50.3.2; python_version == '3.5'
 setuptools==59.6.0; python_version == '3.6'
 setuptools==65.5.1; python_version >= '3.7'
-# wheel 0.38.1 fixes safety issue 51499
-wheel==0.30.0; python_version <= '3.6'
+wheel==0.30.0; python_version == '3.6'
 wheel==0.38.1; python_version >= '3.7'
 
 
@@ -108,25 +38,18 @@ wheel==0.38.1; python_version >= '3.7'
 
 zhmcclient==1.10.0
 
-click==7.0; python_version <= '3.5'
-click==8.0.2; python_version >= '3.6'
-click-repl==0.1.6; python_version <= '3.5'
-click-repl==0.2; python_version >= '3.6'
+click==8.0.2
+click-repl==0.2
 click-spinner==0.1.6
 progressbar2==3.12.0
-# virtualenv 20.0 requires six>=1.12.0 on py>=3.8
-# tox 3.17 requires six>=1.14.0
-six==1.14.0; python_version <= '3.9'
-six==1.16.0; python_version >= '3.10'
 tabulate==0.8.2; python_version <= '3.9'
 tabulate==0.8.8; python_version >= '3.10'
 python-dateutil==2.8.2
 
 # prompt-toolkit is pulled in by click-repl.
-prompt-toolkit==1.0.15; python_version == '2.7'
-prompt-toolkit==2.0.1; python_version >= '3.5'
+prompt-toolkit==2.0.1
 
-# PyYAML is pulled in by zhmcclient and dparse
+# PyYAML is pulled in by zhmccli, zhmcclient, yamlloader
 PyYAML==5.3.1
 
 jsonschema==3.0.1
@@ -140,9 +63,7 @@ pyrsistent==0.15.1
 
 # Indirect dependencies for runtime (must be consistent with requirements.txt)
 
-# certifi 2022.12.07 fixes safety issue 52365
-certifi==2019.9.11; python_version <= '3.5'
-certifi==2023.07.22; python_version >= '3.6'
+certifi==2023.07.22
 chardet==3.0.3
 decorator==4.0.11
 docopt==0.6.2
@@ -152,12 +73,16 @@ pytz==2016.10; python_version <= '3.9'
 pytz==2019.1; python_version >= '3.10'
 stomp.py==4.1.23
 wcwidth==0.2.6
-requests==2.25.0; python_version <= '3.6'
+requests==2.25.0; python_version == '3.6'
 requests==2.31.0; python_version >= '3.7'
 
 
 # Direct dependencies for development (must be consistent with dev-requirements.txt)
 
+# six (only needed by packages that still support Python 2)
+six==1.14.0; python_version <= '3.9'
+six==1.16.0; python_version >= '3.10'
+
 # Tox
 tox==2.5.0
 
@@ -170,57 +95,48 @@ build==0.5.0
 pep517==0.9.1
 
 # Safety CI by pyup.io
-# Safety is run only on Python >=3.6
-safety==2.2.0; python_version >= '3.6'
-dparse==0.6.2; python_version >= '3.6'
+safety==2.2.0
+dparse==0.6.2
 
 # Unit test (imports into testcases):
-# pytest 5.0.0 has removed support for Python < 3.5
 # pytest 4.3.1 solves an issue on Python 3 with minimum package levels
-pytest==4.6.11; python_version <= '3.6' and python_version <= '3.9'
+pytest==4.6.11; python_version >= '3.6' and python_version <= '3.9'
 pytest==6.2.5; python_version >= '3.10'
-importlib-metadata==0.22; python_version <= '3.6'
+importlib-metadata==0.22; python_version == '3.6'
 importlib-metadata==1.1.0; python_version >= '3.7'
 
-packaging==20.5; python_version <= '3.5'
-packaging==21.0; python_version >= '3.6'
+packaging==21.0
 
 # Coverage reporting (no imports, invoked via coveralls script):
 coverage==5.5
 pytest-cov==2.12.1
-# handled by dev-requirements.txt: git+https://github.com/andy-maier/coveralls-python.git@andy/add-py27#egg=coveralls; python_version == '2.7'
-coveralls==3.3.0; python_version >= '3.5'
+coveralls==3.3.0
 
 # Sphinx (no imports, invoked via sphinx-build script):
-Sphinx==1.7.6; python_version == '2.7'
-Sphinx==3.5.4; python_version >= '3.5' and python_version <= '3.9'
+Sphinx==3.5.4; python_version >= '3.6' and python_version <= '3.9'
 Sphinx==4.2.0; python_version >= '3.10'
-docutils==0.13.1; python_version == '2.7'
-docutils==0.13.1; python_version >= '3.5' and python_version <= '3.9'
+docutils==0.13.1; python_version >= '3.6' and python_version <= '3.9'
 docutils==0.14; python_version == '3.10'
 docutils==0.16; python_version >= '3.11'
 sphinx-git==10.1.1
-GitPython==2.1.1; python_version <= '3.6'
+GitPython==2.1.1; python_version == '3.6'
 GitPython==3.1.37; python_version >= '3.7'
 sphinxcontrib-websupport==1.1.2
-Pygments==2.4.1; python_version == '2.7'
-Pygments==2.7.4; python_version >= '3.5' and python_version <= '3.6'
+Pygments==2.7.4; python_version == '3.6'
 Pygments==2.15.0; python_version >= '3.7'
 sphinx-rtd-theme==1.0.0
 Babel==2.9.1
 
 # PyLint (no imports, invoked via pylint script):
-pylint==2.5.2; python_version == '3.5'
 pylint==2.13.0; python_version >= '3.6' and python_version <= '3.10'
 pylint==2.15.0; python_version >= '3.11'
-astroid==2.4.0; python_version == '3.5'
 astroid==2.11.0; python_version >= '3.6' and python_version <= '3.10'
 astroid==2.12.4; python_version >= '3.11'
-typed-ast==1.4.0; python_version >= '3.6' and python_version < '3.8' and implementation_name=='cpython'
-lazy-object-proxy==1.4.3; python_version >= '3.5'
-wrapt==1.12; python_version >= '3.5' and python_version <= '3.10'
+typed-ast==1.4.0; python_version >= '3.6' and python_version <= '3.7' and implementation_name=='cpython'
+lazy-object-proxy==1.4.3
+wrapt==1.12; python_version >= '3.6' and python_version <= '3.10'
 wrapt==1.14; python_version >= '3.11'
-platformdirs==2.2.0; python_version >= '3.6'
+platformdirs==2.2.0
 isort==4.3.8
 tomlkit==0.10.1; python_version >= '3.7'
 dill==0.2; python_version >= '3.6' and python_version <= '3.10'
@@ -235,14 +151,11 @@ pycodestyle==2.8.0; python_version >= '3.10'
 pyflakes==2.2.0; python_version <= '3.9'
 pyflakes==2.4.0; python_version >= '3.10'
 entrypoints==0.3.0
-functools32==3.2.3.post2; python_version == '2.7'  # technically: python_version < '3.2'
 
 # Twine (no imports, invoked via twine script):
-twine==1.8.1; python_version <= '3.5'
-twine==3.0.0; python_version >= '3.6'
+twine==3.0.0
 # readme-renderer (used by twine, uses Pygments)
-readme-renderer==23.0; python_version == '2.7'
-readme-renderer==25.0; python_version >= '3.5'
+readme-renderer==25.0
 
 # Unit test (indirect dependencies):
 # pluggy (used by pytest)
@@ -251,7 +164,7 @@ pluggy==0.13.1
 
 # Package dependency management tools (not used by any make rules)
 pipdeptree==2.2.0
-pip-check-reqs==2.3.2; python_version >= '3.5' and python_version <= '3.7'
+pip-check-reqs==2.3.2; python_version >= '3.6' and python_version <= '3.7'
 pip-check-reqs==2.4.3; python_version >= '3.8'
 
 # Indirect dependencies for development (must be consistent with dev-requirements.txt)
@@ -259,61 +172,47 @@ pip-check-reqs==2.4.3; python_version >= '3.8'
 alabaster==0.7.9
 appdirs==1.4.3
 atomicwrites==1.4.0
-attrs==18.2.0; python_version == '2.7'
-attrs==19.2.0; python_version >= '3.5'
-backports.functools-lru-cache==1.5; python_version == "2.7"
+attrs==19.2.0
 bleach==3.3.0
 # tox 4.0.0 started using cachetools and requires cachetools>=5.2
 cachetools==5.2.0; python_version >= '3.7'
 clint==0.5.1
-colorama==0.3.9; python_version == '2.7'
-colorama==0.4.5; python_version >= '3.5'
+colorama==0.4.5
 configparser==4.0.2
 contextlib2==0.6.0
 distlib==0.3.4
-enum34==1.1.6; python_version == "2.7"
 filelock==3.2.0
-funcsigs==1.0.2; python_version == "2.7"
-futures==3.3.0; python_version == "2.7"
-gitdb2==2.0.0; python_version <= '3.6'
-gitdb==4.0.1; python_version == '3.5'
-gitdb==4.0.8; python_version >= '3.6'
+gitdb2==2.0.0; python_version == '3.6'
+gitdb==4.0.8
 imagesize==0.7.1
 importlib-resources==1.4.0
-iniconfig==2.0.0; python_version >= "3.6"  # used by pytest since its 6.0.0 which requires py36
-Jinja2==2.11.3; python_version <= '3.5'
-Jinja2==3.0.0; python_version >= '3.6'
-keyring==17.0.0; python_version >= '3.5'
-MarkupSafe==1.1.1; python_version <= '3.5'
-MarkupSafe==2.0.0; python_version >= '3.6'
+iniconfig==2.0.0  # used by pytest since its 6.0.0 which requires py36
+Jinja2==3.0.0
+keyring==17.0.0
+MarkupSafe==2.0.0
 more-itertools==5.0.0
 # pathlib2 (used by virtualenv on py<3.4 on non-Windows)
 pathlib2==2.3.3; python_version < '3.4' and sys_platform != 'win32'
 # twine 3.0.0 depends on pkginfo>=1.4.2
 pkginfo==1.4.2
 py==1.11.0
-pyparsing==2.4.7; python_version <= '3.5'
-pyparsing==3.0.7; python_version >= '3.6'
+pyparsing==3.0.7
 # tox 4.0.0 started using pyproject-api and requires pyproject-api>=1.2.1
 pyproject-api==1.2.1; python_version >= '3.7'
 # build is using pyproject-hooks
 pyproject-hooks==1.0.0; python_version >= '3.7'
 requests-toolbelt==0.8.0
-rich==12.0.0; python_version >= '3.6'
-rfc3986==1.3.0; python_version == '3.5'
-rfc3986==1.4.0; python_version >= "3.6"  # used by twine since its 3.2.0 which requires py36
-scandir==1.9.0; python_version == '2.7'
-singledispatch==3.4.0.3; python_version == "2.7"
-smmap2==2.0.1; python_version == '2.7'  # requires smmap>=3.0.1
+rich==12.0.0
+rfc3986==1.4.0  # used by twine since its 3.2.0 which requires py36
 smmap==3.0.1
 snowballstemmer==1.2.1
-sphinxcontrib-applehelp==1.0.0; python_version >= '3.5'
-sphinxcontrib-devhelp==1.0.0; python_version >= '3.5'
-sphinxcontrib-htmlhelp==1.0.0; python_version >= '3.5' and python_version <= '3.9'
+sphinxcontrib-applehelp==1.0.0
+sphinxcontrib-devhelp==1.0.0
+sphinxcontrib-htmlhelp==1.0.0; python_version <= '3.9'
 sphinxcontrib-htmlhelp==2.0.0; python_version >= '3.10'
-sphinxcontrib-jsmath==1.0.0; python_version >= '3.5'
-sphinxcontrib-qthelp==1.0.0; python_version >= '3.5'
-sphinxcontrib-serializinghtml==1.1.5; python_version >= '3.5'
+sphinxcontrib-jsmath==1.0.0
+sphinxcontrib-qthelp==1.0.0
+sphinxcontrib-serializinghtml==1.1.5
 toml==0.10.0  # used by pylint and pytest since some version
 # tomli 2.0.0 removed support for py36
 tomli==1.1.0; python_version == '3.6'
diff --git a/requirements.txt b/requirements.txt
index e97c4c56..9d57a401 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -10,67 +10,39 @@
 # Direct dependencies (except pip, setuptools, wheel):
 
 # zhmcclient @ git+https://github.com/zhmcclient/python-zhmcclient.git@master
-zhmcclient>=1.10.0  # Apache
+zhmcclient>=1.10.0
 
-# click <7.0 did not properly declare supported Python versions
-# click 8.0 has dropped support for Python 2.7,3.5
-# safety 2.2.0 depends on click>=8.0.2 and is run only on Python>=3.6
-click>=7.0,<8.0; python_version <= '3.5'
-click>=8.0.2; python_version >= '3.6'
+# safety 2.2.0 depends on click>=8.0.2
+click>=8.0.2
 
-# click-repl 0.2 is needed for compatibility with Click 8.0 (see issue #819 click-repl incompatible)
-click-repl>=0.1.6; python_version <= '3.5'
-click-repl>=0.2; python_version >= '3.6'
+# click-repl 0.2 is needed for compatibility with Click 8.0 (see click-repl issue #819)
+click-repl>=0.2
 
-click-spinner>=0.1.6 # MIT
-progressbar2>=3.12.0 # BSD
-six>=1.14.0; python_version <= '3.9' # MIT
-six>=1.16.0; python_version >= '3.10' # MIT
-tabulate>=0.8.2; python_version <= '3.9' # MIT
-tabulate>=0.8.8; python_version >= '3.10' # MIT
-python-dateutil>=2.8.2  # Apache, BSD
+click-spinner>=0.1.6
+progressbar2>=3.12.0
+tabulate>=0.8.2; python_version <= '3.9'
+tabulate>=0.8.8; python_version >= '3.10'
+python-dateutil>=2.8.2
 
-# prompt-toolkit is pulled in by click-repl.
 # prompt-toolkit>=2.0 conflicts with ipython and jupyter-console.
-# prompt-toolkit>=3.0 does not support py27.
-prompt-toolkit>=1.0.15,<2.0.0; python_version == '2.7'
-prompt-toolkit>=2.0.1; python_version >= '3.5'
-
-# PyYAML 5.3 has removed support for Python 3.4
-# PyYAML 5.3 fixed narrow build error on Python 2.7
-# PyYAML 5.3.1 addressed issue 38100 reported by safety
-# PyYAML 5.2 addressed issue 38639 reported by safety
-# PyYAML 5.4 fixes safety issue 39611
-# PyYAML 5.3 has wheel archives for Python 2.7, 3.5 - 3.9
-# PyYAML 5.4 has wheel archives for Python 2.7, 3.6 - 3.9
-# PyYAML 6.0 has wheel archives for Python 3.6 - 3.11
-# PyYAML 5.4 and 6.0.0 fails install since Cython 3 was released, see issue
-#   https://github.com/yaml/pyyaml/issues/724.
-PyYAML>=5.3.1; python_version <= '3.5'
-PyYAML>=5.3.1,!=5.4.0,!=5.4.1; python_version >= '3.6' and python_version <= '3.11'
+prompt-toolkit>=2.0.1
+
+# PyYAML 5.3.x has wheel archives for Python 2.7, 3.5 - 3.9
+# PyYAML 5.4.x has wheel archives for Python 2.7, 3.6 - 3.9
+# PyYAML 6.0.0 has wheel archives for Python 3.6 - 3.11
+# PyYAML 6.0.1 has wheel archives for Python 3.6 - 3.12
+# PyYAML versions without wheel archives fail install since Cython 3 was
+#   released, see https://github.com/yaml/pyyaml/issues/724.
+PyYAML>=5.3.1,!=5.4.0,!=5.4.1; python_version <= '3.11'
 PyYAML>=5.3.1,!=5.4.0,!=5.4.1,!=6.0.0; python_version >= '3.12'
 
 jsonschema>=3.0.1
 yamlloader>=0.5.5
 
-# urllib3 is used to disable warnings
-urllib3>=1.26.5  # MIT
+urllib3>=1.26.5
 
 
-# Indirect dependencies (commented out, only listed to document their license):
+# Indirect dependencies that need to be adjusted for some reason:
 
-# MIT, from jsonschema>=3.0
-# pyrsistent 0.15.0 started using the FileNotFoundError built-in exception that
-# was added only in Python 3. pyrsistent 0.15.1 fixed that by defining it locally for py27.
+# pyrsistent is used by jsonschema 3.x (no longer by jsonschema 4.x)
 pyrsistent>=0.15.1
-
-# certifi # MPL 2.0, from requests
-# chardet # LGPL, from requests
-# decorator # BSD, from zhmcclient
-# docopt # MIT, from stomp.py
-# idna # BSD, from requests
-# python-utils # BSD, from progressbar2
-# pytz # MIT, from zhmcclient
-# requests # Apache, from zhmcclient
-# stomp.py # Apache, from zhmcclient
-# wcwidth # MIT, from prompt-toolkit
diff --git a/setup.py b/setup.py
index 4014cd2a..f9388c40 100644
--- a/setup.py
+++ b/setup.py
@@ -115,7 +115,7 @@ def read_file(a_file):
     # Keep these Python versions in sync with:
     # - Section "Supported environments" in docs/intro.rst
     # - Version checking in zhmccli/_version.py
-    python_requires='>=2.7, !=3.0.*, !=3.1.*, !=3.2.*, !=3.3.*, !=3.4.*',
+    python_requires='>=3.6',
     classifiers=[
         'Development Status :: 5 - Production/Stable',
         'Environment :: Console',
@@ -123,10 +123,7 @@ def read_file(a_file):
         'Intended Audience :: Information Technology',
         'License :: OSI Approved :: Apache Software License',
         'Operating System :: OS Independent',
-        'Programming Language :: Python :: 2',
-        'Programming Language :: Python :: 2.7',
         'Programming Language :: Python :: 3',
-        'Programming Language :: Python :: 3.5',
         'Programming Language :: Python :: 3.6',
         'Programming Language :: Python :: 3.7',
         'Programming Language :: Python :: 3.8',
diff --git a/tests/end2end/utils.py b/tests/end2end/utils.py
index 1197dac0..2e60a251 100644
--- a/tests/end2end/utils.py
+++ b/tests/end2end/utils.py
@@ -23,7 +23,6 @@
 import subprocess
 import random
 import warnings
-import six
 import pytest
 import zhmcclient
 
@@ -187,7 +186,7 @@ def run_zhmc(args, env=None, pdb_=False, log=False):
 
     stdout, stderr = proc.communicate()
     rc = proc.returncode
-    if six.PY3 and not pdb_:
+    if not pdb_:
         stdout = stdout.decode()
         stderr = stderr.decode()
 
diff --git a/tests/function/utils.py b/tests/function/utils.py
index 6a30c638..9e12870d 100644
--- a/tests/function/utils.py
+++ b/tests/function/utils.py
@@ -24,7 +24,6 @@
 import tempfile
 from subprocess import Popen, PIPE
 from copy import copy
-import six
 
 import zhmcclient_mock
 from zhmccli.zhmccli import cli
@@ -97,7 +96,7 @@ def call_zhmc_child(args, env=None):
     assert isinstance(args, (list, tuple))
     cmd_args = [cli_cmd]
     for arg in args:
-        if not isinstance(arg, six.text_type):
+        if isinstance(arg, bytes):
             arg = arg.decode('utf-8')
         cmd_args.append(arg)
 
@@ -112,9 +111,9 @@ def call_zhmc_child(args, env=None):
     stdout_str, stderr_str = proc.communicate()
     rc = proc.returncode
 
-    if isinstance(stdout_str, six.binary_type):
+    if isinstance(stdout_str, bytes):
         stdout_str = stdout_str.decode('utf-8')
-    if isinstance(stderr_str, six.binary_type):
+    if isinstance(stderr_str, bytes):
         stderr_str = stderr_str.decode('utf-8')
 
     return rc, stdout_str, stderr_str
@@ -201,7 +200,7 @@ def call_zhmc_inline(args, env=None, faked_session=None):
     assert isinstance(args, (list, tuple))
     sys.argv = [cli_cmd]
     for arg in args:
-        if not isinstance(arg, six.text_type):
+        if isinstance(arg, bytes):
             arg = arg.decode('utf-8')
         sys.argv.append(arg)
 
@@ -255,9 +254,9 @@ def local_exit(rc):
         tmp_stdout.seek(0)
         stdout_str = tmp_stdout.read()
 
-    if isinstance(stdout_str, six.binary_type):
+    if isinstance(stdout_str, bytes):
         stdout_str = stdout_str.decode('utf-8')
-    if isinstance(stderr_str, six.binary_type):
+    if isinstance(stderr_str, bytes):
         stderr_str = stderr_str.decode('utf-8')
 
     # Note that the click package on Windows writes '\n' at the Python level
diff --git a/tox.ini b/tox.ini
index ad311567..e3b461b3 100644
--- a/tox.ini
+++ b/tox.ini
@@ -9,18 +9,12 @@
 [tox]
 minversion = 2.0
 envlist =
-    py27
-    py35
     py36
     py37
     py38
     py39
     py310
     py311
-    win64_py27_32
-    win64_py27_64
-    win64_py35_32
-    win64_py35_64
     win64_py36_32
     win64_py36_64
     win64_py37_32
@@ -33,10 +27,7 @@ envlist =
     win64_py310_64
     win64_py311_32
     win64_py311_64
-    cygwin32_py27
-    cygwin64_py27
     cygwin64_py36
-    msys64_py27
 
 skip_missing_interpreters = true
 
@@ -75,14 +66,6 @@ commands =
     make develop pip_list
     sh -c "export TESTCASES={posargs}; make test"
 
-[testenv:py27]
-platform = linux2|darwin
-basepython = python2.7
-
-[testenv:py35]
-platform = linux2|darwin
-basepython = python3.5
-
 [testenv:py36]
 platform = linux2|darwin
 basepython = python3.6
@@ -110,30 +93,6 @@ basepython = python3.11
 # Note: The basepython file paths for the win64* tox environments may need to
 #       be customized.
 
-[testenv:win64_py27_32]
-platform = win32
-basepython = python
-setenv =
-    PATH = C:\Python27;{env:PATH}
-
-[testenv:win64_py27_64]
-platform = win32
-basepython = python
-setenv =
-    PATH = C:\Python27-x64;{env:PATH}
-
-[testenv:win64_py35_32]
-platform = win32
-basepython = python
-setenv =
-    PATH = C:\Python35;{env:PATH}
-
-[testenv:win64_py35_64]
-platform = win32
-basepython = python
-setenv =
-    PATH = C:\Python35-x64;{env:PATH}
-
 [testenv:win64_py36_32]
 platform = win32
 basepython = python
@@ -206,18 +165,6 @@ basepython = python
 setenv =
     PATH = C:\Python311-x64;{env:PATH}
 
-[testenv:cygwin32_py27]
-platform = cygwin
-basepython = python2.7
-
-[testenv:cygwin64_py27]
-platform = cygwin
-basepython = python2.7
-
 [testenv:cygwin64_py36]
 platform = cygwin
 basepython = python3.6m
-
-[testenv:msys64_py27]
-platform = msys
-basepython = python2.7
diff --git a/zhmccli/_helper.py b/zhmccli/_helper.py
index cd0e6d8e..3b6c3ef5 100644
--- a/zhmccli/_helper.py
+++ b/zhmccli/_helper.py
@@ -26,7 +26,6 @@
 import threading
 import re
 import jsonschema
-import six
 import click
 import click_spinner
 from tabulate import tabulate
@@ -430,7 +429,7 @@ def original_options(options):
       dict: Options with their original names.
     """
     org_options = {}
-    for name, value in six.iteritems(options):
+    for name, value in options.items():
         org_name = name.replace('_', '-')
         org_options[org_name] = value
     return org_options
@@ -464,7 +463,7 @@ def options_to_properties(options, name_map=None):
       dict: Resource properties (key: property name, value: option value)
     """
     properties = {}
-    for name, value in six.iteritems(options):
+    for name, value in options.items():
         if value is None:
             continue
         if name_map:
@@ -1138,7 +1137,7 @@ def join(self, timeout=None):
         """
         super(ExceptionThread, self).join(timeout)
         if self.exc_info:
-            six.reraise(*self.exc_info)
+            raise self.exc_info.value
 
 
 def console_log(logger, prefix, message, *args, **kwargs):
@@ -1273,7 +1272,7 @@ def part_console(session, part, refresh, logger):
     while True:
         try:
             # This has history/ editing support when readline is imported
-            line = six.moves.input()
+            line = input()
         except EOFError:
             # CTRL-D was pressed
             reason = "CTRL-D"
@@ -1330,7 +1329,7 @@ def click_exception(exc, error_format):
         elif isinstance(exc, Exception):
             error_str = str(exc)
         else:
-            assert isinstance(exc, six.string_types)
+            assert isinstance(exc, str)
             error_str = "classname: None, message: {msg}".format(msg=exc)
     else:
         assert error_format == 'msg'
@@ -1338,7 +1337,7 @@ def click_exception(exc, error_format):
             error_str = "{exc}: {msg}".format(
                 exc=exc.__class__.__name__, msg=exc)
         else:
-            assert isinstance(exc, six.string_types)
+            assert isinstance(exc, str)
             error_str = exc
     new_exc = click.ClickException(error_str)
     new_exc.__cause__ = None