Drop support for Python < 3.7 (#386)

* Bumped version for breaking release.

* Drop support for Python 2.7, 3.5, 3.6.

---------

Co-authored-by: Jens Vagelpohl <jens@plyp.com>

Author: Michael Howitz

.github/workflows/tests.yml

@@ -22,24 +22,19 @@ jobs:
         config:
         # [Python version, tox env]
         - ["3.9",   "lint"]
-        - ["2.7",   "py27"]
-        - ["3.5",   "py35"]
-        - ["3.6",   "py36"]
         - ["3.7",   "py37"]
         - ["3.8",   "py38"]
         - ["3.9",   "py39"]
         - ["3.10",  "py310"]
         - ["3.11",  "py311"]
-        - ["pypy-2.7", "pypy"]
-        - ["pypy-3.7", "pypy3"]
+        - ["pypy-3.9", "pypy3"]
         - ["3.9",   "docs"]
         - ["3.9",   "coverage"]
-        - ["3.8",   "py38-pure"]
+        - ["3.10",   "py310-pure"]
         exclude:
           - { os: ["windows", "windows-latest"], config: ["3.9",   "lint"] }
           - { os: ["windows", "windows-latest"], config: ["3.9",   "docs"] }
           - { os: ["windows", "windows-latest"], config: ["3.9",   "coverage"] }
-          - { os: ["windows", "windows-latest"], config: ["pypy-2.7", "pypy"] }
 
     runs-on: ${{ matrix.os[1] }}
     if: github.event_name != 'pull_request' || github.event.pull_request.head.repo.full_name != github.event.pull_request.base.repo.full_name
@@ -67,7 +62,7 @@ jobs:
     - name: Coverage
       if: matrix.config[1] == 'coverage'
       run: |
-        pip install coveralls coverage-python-version
+        pip install coveralls
         coveralls --service=github
       env:
         GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.meta.toml

@@ -2,15 +2,15 @@
 # https://github.com/zopefoundation/meta/tree/master/config/pure-python
 [meta]
 template = "pure-python"
-commit-id = "b4dd6f9ffd3d6a2cde7dc70512c62d4c7ed22cd6"
+commit-id = "b99ba750"
 
 [python]
 with-windows = true
 with-pypy = true
 with-future-python = false
-with-legacy-python = true
 with-docs = true
 with-sphinx-doctests = false
+with-macos = false
 
 [tox]
 use-flake8 = true
@@ -21,12 +21,12 @@ testenv-setenv = [
     "ZOPE_INTERFACE_STRICT_IRO=1",
     ]
 additional-envlist = [
-    "py38-pure",
+    "py310-pure",
     ]
 testenv-additional = [
     "",
-    "[testenv:py38-pure]",
-    "basepython = python3.8",
+    "[testenv:py310-pure]",
+    "basepython = python3.10",
     "setenv =",
     "    PURE_PYTHON = 1",
     ]
@@ -67,8 +67,5 @@ additional-ignores = [
 
 [github-actions]
 additional-config = [
-    "- [\"3.8\",   \"py38-pure\"]",
-    ]
-additional-exclude = [
-    "- { os: windows, config: [\"pypy-2.7\", \"pypy\"] }",
+    "- [\"3.10\",   \"py310-pure\"]",
     ]

CHANGES.rst

@@ -2,8 +2,10 @@
  Change History
 ================
 
-5.8.2 (unreleased)
-==================
+6.0 (unreleased)
+================
+
+- Drop support for Python 2.7, 3.5, 3.6.
 
 
 5.8.1 (2023-07-18)

setup.cfg

@@ -1,7 +1,7 @@
 # Generated from:
 # https://github.com/zopefoundation/meta/tree/master/config/pure-python
 [bdist_wheel]
-universal = 1
+universal = 0
 
 [flake8]
 doctests = 1
@@ -26,7 +26,7 @@ ignore =
 force_single_line = True
 combine_as_imports = True
 sections = FUTURE,STDLIB,THIRDPARTY,ZOPE,FIRSTPARTY,LOCALFOLDER
-known_third_party = six, docutils, pkg_resources
+known_third_party = docutils, pkg_resources, pytz
 known_zope =
 known_first_party =
 default_section = ZOPE

setup.py

@@ -15,30 +15,7 @@
 from setuptools import setup
 
 
-version = '5.8.2.dev0'
-
-classifiers = """\
-Intended Audience :: Developers
-License :: OSI Approved :: Zope Public License
-Programming Language :: Python
-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
-Programming Language :: Python :: 3.9
-Programming Language :: Python :: 3.10
-Programming Language :: Python :: 3.11
-Programming Language :: Python :: Implementation :: CPython
-Programming Language :: Python :: Implementation :: PyPy
-Topic :: Database
-Topic :: Software Development :: Libraries :: Python Modules
-Operating System :: Microsoft :: Windows
-Operating System :: Unix
-Framework :: ZODB
-"""
+version = '6.0.dev0'
 
 
 def read(path):
@@ -50,7 +27,6 @@ def read(path):
 
 tests_require = [
     'manuel',
-    'mock; python_version == "2.7"',
     'zope.testing',
     'zope.testrunner >= 4.4.6',
 ]
@@ -61,14 +37,31 @@ def read(path):
     author="Jim Fulton",
     author_email="jim@zope.com",
     maintainer="Zope Foundation and Contributors",
-    maintainer_email="zodb-dev@zope.org",
+    maintainer_email="zodb-dev@zope.dev",
     keywords="database nosql python zope",
     packages=find_packages('src'),
     package_dir={'': 'src'},
     url='http://zodb-docs.readthedocs.io',
     license="ZPL 2.1",
     platforms=["any"],
-    classifiers=list(filter(None, classifiers.split("\n"))),
+    classifiers=[
+        "Intended Audience :: Developers",
+        "License :: OSI Approved :: Zope Public License",
+        "Programming Language :: Python",
+        "Programming Language :: Python :: 3",
+        "Programming Language :: Python :: 3.7",
+        "Programming Language :: Python :: 3.8",
+        "Programming Language :: Python :: 3.9",
+        "Programming Language :: Python :: 3.10",
+        "Programming Language :: Python :: 3.11",
+        "Programming Language :: Python :: Implementation :: CPython",
+        "Programming Language :: Python :: Implementation :: PyPy",
+        "Topic :: Database",
+        "Topic :: Software Development :: Libraries :: Python Modules",
+        "Operating System :: Microsoft :: Windows",
+        "Operating System :: Unix",
+        "Framework :: ZODB",
+    ],
     description=long_description.split('\n', 2)[1],
     long_description=long_description,
     tests_require=tests_require,
@@ -87,7 +80,6 @@ def read(path):
         'BTrees >= 4.2.0',
         'ZConfig',
         'transaction >= 2.4',
-        'six',
         'zc.lockfile',
         'zope.interface',
         'zodbpickle >= 1.0.1',
@@ -102,5 +94,5 @@ def read(path):
       repozo = ZODB.scripts.repozo:main
     """,
     include_package_data=True,
-    python_requires='>=2.7,!=3.0.*,!=3.1.*,!=3.2.*,!=3.3.*,!=3.4.*',
+    python_requires='>=3.7',
 )

src/ZODB/ActivityMonitor.py

@@ -19,7 +19,7 @@
 from . import utils
 
 
-class ActivityMonitor(object):
+class ActivityMonitor:
     """ZODB load/store activity monitor
 
     This simple implementation just keeps a small log in memory

src/ZODB/BaseStorage.py

@@ -16,7 +16,6 @@
 The base class here is tightly coupled with its subclasses and
 its use is not recommended.  It's still here for historical reasons.
 """
-from __future__ import print_function
 
 import logging
 import time
@@ -30,7 +29,6 @@
 
 from . import POSException
 from . import utils
-from ._compat import py2_hasattr
 from .Connection import TransactionMetaData
 from .UndoLogCompatible import UndoLogCompatible
 from .utils import byte_chr
@@ -310,7 +308,12 @@ def copy(source, dest, verbose=0):
     # using store().  However, if we use store, then
     # copyTransactionsFrom() may fail with VersionLockError or
     # ConflictError.
-    restoring = py2_hasattr(dest, 'restore')
+    try:
+        getattr(dest, 'restore')
+    except:  # noqa: E722 do not use bare 'except'
+        restoring = False
+    else:
+        restoring = True
     fiter = source.iterator()
     for transaction in fiter:
         tid = transaction.tid
@@ -320,14 +323,14 @@ def copy(source, dest, verbose=0):
             t = TimeStamp(tid)
             if t <= _ts:
                 if ok:
-                    print(('Time stamps out of order %s, %s' % (_ts, t)))
+                    print('Time stamps out of order {}, {}'.format(_ts, t))
                 ok = 0
                 _ts = t.laterThan(_ts)
                 tid = _ts.raw()
             else:
                 _ts = t
                 if not ok:
-                    print(('Time stamps back in order %s' % (t)))
+                    print('Time stamps back in order %s' % (t))
                     ok = 1
 
         if verbose:
@@ -376,7 +379,7 @@ def __init__(self, tid, status, user, description, extension):
 
 
 @zope.interface.implementer(ZODB.interfaces.IStorageRecordInformation)
-class DataRecord(object):
+class DataRecord:
     """Abstract base class for iterator protocol"""
 
     version = ''

src/ZODB/ConflictResolution.py

@@ -13,16 +13,11 @@
 ##############################################################################
 
 import logging
-# Subtle: Python 2.x has pickle.PicklingError and cPickle.PicklingError,
-# and these are unrelated classes!  So we shouldn't use pickle.PicklingError,
-# since on Python 2, ZODB._compat.pickle is cPickle.
+from io import BytesIO
 from pickle import PicklingError
 
-import six
-
 import zope.interface
 
-from ZODB._compat import BytesIO
 from ZODB._compat import PersistentPickler
 from ZODB._compat import PersistentUnpickler
 from ZODB._compat import _protocol
@@ -37,7 +32,7 @@ class BadClassName(Exception):
     pass
 
 
-class BadClass(object):
+class BadClass:
 
     def __init__(self, *args):
         self.args = args
@@ -68,8 +63,8 @@ def find_global(*args):
     if cls == 1:
         # Not importable
         if (isinstance(args, tuple) and len(args) == 2 and
-                isinstance(args[0], six.string_types) and
-                isinstance(args[1], six.string_types)):
+                isinstance(args[0], str) and
+                isinstance(args[1], str)):
             return BadClass(*args)
         else:
             raise BadClassName(*args)
@@ -125,7 +120,7 @@ class may have its own comparison, and we have no idea what it is.
 
 
 @zope.interface.implementer(IPersistentReference)
-class PersistentReference(object):
+class PersistentReference:
 
     weak = False
     oid = database_name = klass = None
@@ -169,7 +164,7 @@ def __init__(self, data):
                 self.weak = True
         if not isinstance(self.oid, (bytes, type(None))):
             assert isinstance(self.oid, str)
-            # this happens on Python 3 when all bytes in the oid are < 0x80
+            # this happens when all bytes in the oid are < 0x80
             self.oid = self.oid.encode('ascii')
 
     def __cmp__(self, other):
@@ -185,8 +180,6 @@ def __cmp__(self, other):
                 "can't reliably compare against different "
                 "PersistentReferences")
 
-    # Python 3 dropped __cmp__
-
     def __eq__(self, other):
         return self.__cmp__(other) == 0
 
@@ -206,7 +199,7 @@ def __ge__(self, other):
         return self.__cmp__(other) >= 0
 
     def __repr__(self):
-        return "PR(%s %s)" % (id(self), self.data)
+        return "PR({} {})".format(id(self), self.data)
 
     def __getstate__(self):
         raise PicklingError("Can't pickle PersistentReference")
@@ -221,7 +214,7 @@ def klass(self):
             return data[1][2]
 
 
-class PersistentReferenceFactory(object):
+class PersistentReferenceFactory:
 
     data = None
 
@@ -311,7 +304,7 @@ def tryToResolveConflict(self, oid, committedSerial, oldSerial, newpickle,
                         data=newpickle)
 
 
-class ConflictResolvingStorage(object):
+class ConflictResolvingStorage:
     "Mix-in class that provides conflict resolution handling for storages"
 
     tryToResolveConflict = tryToResolveConflict
@@ -323,7 +316,7 @@ def registerDB(self, wrapper):
         self._crs_untransform_record_data = wrapper.untransform_record_data
         self._crs_transform_record_data = wrapper.transform_record_data
         try:
-            m = super(ConflictResolvingStorage, self).registerDB
+            m = super().registerDB
         except AttributeError:
             pass
         else: