upgrade: removing support for depreciated python 3.6

Author: lhaze

.github/workflows/code_quality.yml

@@ -32,7 +32,6 @@ jobs:
         platform:
           - ubuntu-latest
         python-version:
-          - "3.6"
           - "3.7"
           - "3.8"
           - "3.9"

pyproject.toml

@@ -36,19 +36,14 @@ packages = [
 ]
 
 [tool.poetry.dependencies]
-python = "^3.6.1"
-
-dataclasses = {version = "^0.8", python = "3.6"}
+python = "^3.7"
 
 [tool.poetry.dev-dependencies]
 
 black = {version = "^20.8b1", markers = "platform_python_implementation!='PyPy'"}
 coverage = "^5.3"
 flake8 = "^3.8.4"
-ipython = [
-    {version = "^7.32.0", python = "^3.7"},
-    {version = "~7.16.3", python = "3.6"},
-]
+ipython = "^7.32.0"
 isort = "^5.6.4"
 mock = "^4.0.2"
 pdbpp = "^0.10.2"

tests/test_boundary.py

@@ -1,5 +1,3 @@
-import sys
-
 from collections import namedtuple
 
 import mock
@@ -8,8 +6,6 @@
 from pca.packages.errors import ErrorBoundary
 
 
-PY36 = (3, 6) <= sys.version_info < (3, 7)
-
 Callbacks = namedtuple(
     "Callbacks",
     [
@@ -162,10 +158,6 @@ class TestCallbackErrors:
     Tests checking what happens when a callback throws an error.
     """
 
-    @pytest.mark.skipif(
-        PY36,
-        reason="strange behavior of representing Exception.args on CPython 3.6.15; waiting for obsoletion for Py36",
-    )
     def test_log_inner_error(self, caplog) -> None:
         main_exception = AnException("main_exception")
         callback_exception = AnotherException("callback_exception")

tox.ini

@@ -3,7 +3,6 @@ isolated_build = true
 usedevelop = True
 envlist =
   clean
-  py36
   py37
   py38
   py39
@@ -12,7 +11,6 @@ envlist =
 
 [gh-actions]
 python =
-    3.6: py36
     3.7: py37
     3.8: py38
     3.9: py39