Drop python3.6 and make simplifications

.github/workflows/ci.yml

@@ -13,7 +13,7 @@ jobs:
       fail-fast: false
       # Run tests on each OS/Python combination
       matrix:
-        python-version: ["3.6", "3.7", "3.8", "3.9", "3.10"]
+        python-version: ["3.7", "3.8", "3.9", "3.10"]
         # TODO: Add windows-latest when gpg issues are solved
         os: [ubuntu-latest, macos-latest]
         toxenv: [py]

requirements.txt

@@ -16,7 +16,7 @@
 # 1. Use this script to create a pinned requirements file for each Python
 #    version
 # ```
-# for v in 3.6 3.7 3.8 3.9; do
+# for v in 3.7 3.8 3.9; do
 #   mkvirtualenv sslib-env-${v} -p python${v};
 #   pip install pip-tools;
 #   pip-compile --no-header -o requirements-${v}.txt requirements.txt;

setup.py

@@ -88,7 +88,6 @@
     'Operating System :: MacOS :: MacOS X',
     'Operating System :: Microsoft :: Windows',
     'Programming Language :: Python :: 3',
-    'Programming Language :: Python :: 3.6',
     'Programming Language :: Python :: 3.7',
     'Programming Language :: Python :: 3.8',
     'Programming Language :: Python :: 3.9',
@@ -101,7 +100,7 @@
     'Source': 'https://github.com/secure-systems-lab/securesystemslib',
     'Issues': 'https://github.com/secure-systems-lab/securesystemslib/issues',
   },
-  python_requires = "~=3.6",
+  python_requires = "~=3.7",
   extras_require = {
       'colors': ['colorama>=0.3.9'],
       'crypto': ['cryptography>=3.3.2'],

tests/test_hash.py

@@ -45,9 +45,6 @@ def _is_supported_combination(library, algorithm):
     if algorithm in blake_algos:
       if library == 'pyca_crypto':
         return False
-      # hashlib does not support blake2* if < 3.6
-      elif library == 'hashlib' and sys.version_info[:2] < (3, 6):
-        return False
     return True
 
 

tests/test_signer.py

@@ -9,18 +9,7 @@
 import securesystemslib.formats
 import securesystemslib.keys as KEYS
 from securesystemslib.exceptions import FormatError, UnsupportedAlgorithmError
-
-# TODO: Remove case handling when fully dropping support for versions < 3.6
-IS_PY_VERSION_SUPPORTED = sys.version_info >= (3, 6)
-
-# Use setUpModule to tell unittest runner to skip this test module gracefully.
-def setUpModule():
-    if not IS_PY_VERSION_SUPPORTED:
-        raise unittest.SkipTest("requires Python 3.6 or higher")
-
-# Since setUpModule is called after imports we need to import conditionally.
-if IS_PY_VERSION_SUPPORTED:
-    from securesystemslib.signer import Signature, SSlibSigner
+from securesystemslib.signer import Signature, SSlibSigner
 
 
 class TestSSlibSigner(unittest.TestCase):

tox.ini

@@ -4,7 +4,7 @@
 # and then run "tox" from this directory.
 
 [tox]
-envlist = mypy, py36, py37, py38, py39, py310, purepy38, py38-no-gpg
+envlist = mypy, py37, py38, py39, py310, purepy38, py38-no-gpg
 skipsdist = True
 
 [testenv]