Merge pull request #510 from cherrypy/debt/py36

Drop support for Python 3.5 and 2.7

.github/workflows/ci-cd.yml

@@ -638,14 +638,11 @@ jobs:
         - 3.11
         - >-
           3.10
-        - pypy2.7-v7.3.9
         - 3.9
         - 3.8
         - pypy-3.7
         - 3.7
         - 3.6
-        - 3.5
-        - 2.7
         - pypy-3.6
         os:
         - ubuntu-20.04
@@ -658,10 +655,6 @@ jobs:
         # NOTE: Windows PyPy jobs are excluded to address the tox bug
         # NOTE: https://github.com/tox-dev/tox/issues/1704.
         # NOTE: They should be re-added once it's fixed.
-        - os: windows-2022
-          python-version: pypy2.7-v7.3.9
-        - os: windows-2019
-          python-version: pypy2.7-v7.3.9
         - os: windows-2022
           python-version: pypy-3.6
         - os: windows-2019
@@ -676,23 +669,14 @@ jobs:
         # NOTE: macOS PyPy jobs are excluded because installing cryptography
         # NOTE: needs openssl headers that aren't present at the moment.
         # TODO: Remove the exclusions once this is addressed.
-        - os: macos-11.0
-          python-version: pypy2.7-v7.3.9
-        - os: macos-latest
-          python-version: pypy2.7-v7.3.9
-        - os: macos-11.0
+        - os: macOS-11.0
           python-version: pypy-3.6
         - os: macos-latest
           python-version: pypy-3.6
         - os: macos-11.0
           python-version: pypy-3.7
         - os: macos-latest
           python-version: pypy-3.7
-        include:
-        # NOTE: The only GNU/Linux CPython 3.4 available is built for Ubuntu 18
-        # https://github.com/actions/python-versions/blob/c483657/versions-manifest.json#L1228
-        - os: ubuntu-18.04
-          python-version: 3.4
 
     continue-on-error: >-
       ${{
@@ -704,22 +688,15 @@ jobs:
             (
               startsWith(matrix.python-version, '~')
             ) ||
-            (
-              matrix.python-version == '2.7' &&
-              startsWith(matrix.os, 'windows-')
-            )
+            contains(matrix.python-version, 'alpha')
           ) && true || false
       }}
 
     env:
-      PYTEST_ADDOPTS: >-
-        ${{
-            (
-                matrix.python-version == 'pypy2.7-v7.3.9' &&
-                startsWith(matrix.os, 'ubuntu-')
-            ) &&
-            '-p no:warnings' || ''
-        }}
+      PIP_DISABLE_PIP_VERSION_CHECK: 1
+      PIP_NO_PYTHON_VERSION_WARNING: 1
+      PIP_NO_WARN_SCRIPT_LOCATION: 1
+      PY_COLORS: 1
       TOXENV: python
 
     steps:

CHANGES.rst

@@ -1,3 +1,11 @@
+.. scm-version-title:: v9.0.0
+
+- :issue:`252` via :pr:`339`: Cheroot now requires Python
+  3.6 or later. Python 3.5 and Python 2.7 are still supported
+  by the :gh:`maint/8.x branch
+  <cherrypy/cheroot/tree/maint/8.x>` and stabilizing
+  bugfixes will be accepted to that branch.
+
 .. scm-version-title:: v8.6.0
 
 Significant improvements:

cheroot/__init__.py

@@ -1,8 +1,5 @@
 """High-performance, pure-Python HTTP server used by CherryPy."""
 
-from __future__ import absolute_import, division, print_function
-__metaclass__ = type
-
 try:
     from importlib import metadata
 except ImportError:

cheroot/_compat.py

@@ -1,19 +1,9 @@
 # pylint: disable=unused-import
 """Compatibility code for using Cheroot with various versions of Python."""
 
-from __future__ import absolute_import, division, print_function
-__metaclass__ = type
-
 import os
 import platform
-import re
-
-import six
 
-try:
-    import selectors  # lgtm [py/unused-import]
-except ImportError:
-    import selectors2 as selectors  # noqa: F401  # lgtm [py/unused-import]
 
 try:
     import ssl
@@ -22,20 +12,6 @@
 except ImportError:
     IS_ABOVE_OPENSSL10 = None
 
-# contextlib.suppress was added in Python 3.4
-try:
-    from contextlib import suppress
-except ImportError:
-    from contextlib import contextmanager
-
-    @contextmanager
-    def suppress(*exceptions):
-        """Return a context manager that suppresses the `exceptions`."""
-        try:
-            yield
-        except exceptions:
-            pass
-
 
 IS_CI = bool(os.getenv('CI'))
 IS_GITHUB_ACTIONS_WORKFLOW = bool(os.getenv('GITHUB_WORKFLOW'))
@@ -53,53 +29,23 @@ def suppress(*exceptions):
 IS_PPC = PLATFORM_ARCH.startswith('ppc')
 
 
-if not six.PY2:
-    def ntob(n, encoding='ISO-8859-1'):
-        """Return the native string as bytes in the given encoding."""
-        assert_native(n)
-        # In Python 3, the native string type is unicode
-        return n.encode(encoding)
-
-    def ntou(n, encoding='ISO-8859-1'):
-        """Return the native string as Unicode with the given encoding."""
-        assert_native(n)
-        # In Python 3, the native string type is unicode
-        return n
-
-    def bton(b, encoding='ISO-8859-1'):
-        """Return the byte string as native string in the given encoding."""
-        return b.decode(encoding)
-else:
-    # Python 2
-    def ntob(n, encoding='ISO-8859-1'):
-        """Return the native string as bytes in the given encoding."""
-        assert_native(n)
-        # In Python 2, the native string type is bytes. Assume it's already
-        # in the given encoding, which for ISO-8859-1 is almost always what
-        # was intended.
-        return n
-
-    def ntou(n, encoding='ISO-8859-1'):
-        """Return the native string as Unicode with the given encoding."""
-        assert_native(n)
-        # In Python 2, the native string type is bytes.
-        # First, check for the special encoding 'escape'. The test suite uses
-        # this to signal that it wants to pass a string with embedded \uXXXX
-        # escapes, but without having to prefix it with u'' for Python 2,
-        # but no prefix for Python 3.
-        if encoding == 'escape':
-            return re.sub(
-                r'\\u([0-9a-zA-Z]{4})',
-                lambda m: six.unichr(int(m.group(1), 16)),
-                n.decode('ISO-8859-1'),
-            )
-        # Assume it's already in the given encoding, which for ISO-8859-1
-        # is almost always what was intended.
-        return n.decode(encoding)
-
-    def bton(b, encoding='ISO-8859-1'):
-        """Return the byte string as native string in the given encoding."""
-        return b
+def ntob(n, encoding='ISO-8859-1'):
+    """Return the native string as bytes in the given encoding."""
+    assert_native(n)
+    # In Python 3, the native string type is unicode
+    return n.encode(encoding)
+
+
+def ntou(n, encoding='ISO-8859-1'):
+    """Return the native string as Unicode with the given encoding."""
+    assert_native(n)
+    # In Python 3, the native string type is unicode
+    return n
+
+
+def bton(b, encoding='ISO-8859-1'):
+    """Return the byte string as native string in the given encoding."""
+    return b.decode(encoding)
 
 
 def assert_native(n):
@@ -113,17 +59,6 @@ def assert_native(n):
         raise TypeError('n must be a native str (got %s)' % type(n).__name__)
 
 
-if not six.PY2:
-    """Python 3 has :py:class:`memoryview` builtin."""
-    # Python 2.7 has it backported, but socket.write() does
-    # str(memoryview(b'0' * 100)) -> <memory at 0x7fb6913a5588>
-    # instead of accessing it correctly.
-    memoryview = memoryview
-else:
-    """Link :py:class:`memoryview` to buffer under Python 2."""
-    memoryview = buffer  # noqa: F821
-
-
 def extract_bytes(mv):
     r"""Retrieve bytes out of the given input buffer.
 
@@ -138,7 +73,7 @@ def extract_bytes(mv):
                         or :py:class:`bytes`
     """
     if isinstance(mv, memoryview):
-        return bytes(mv) if six.PY2 else mv.tobytes()
+        return mv.tobytes()
 
     if isinstance(mv, bytes):
         return mv

cheroot/_compat.pyi

@@ -2,8 +2,6 @@ from typing import Any, ContextManager, Optional, Type, Union
 
 def suppress(*exceptions: Type[BaseException]) -> ContextManager[None]: ...
 
-selectors: Any
-
 IS_ABOVE_OPENSSL10: Optional[bool]
 IS_CI: bool
 IS_GITHUB_ACTIONS_WORKFLOW: bool
@@ -20,6 +18,4 @@ def ntou(n: str, encoding: str = ...) -> str: ...
 def bton(b: bytes, encoding: str = ...) -> str: ...
 def assert_native(n: str) -> None: ...
 
-memoryview: Any
-
 def extract_bytes(mv: Union[memoryview, bytes]) -> bytes: ...

cheroot/cli.py

@@ -28,18 +28,14 @@
 """
 
 import argparse
-from importlib import import_module
 import os
 import sys
-
-import six
+import urllib.parse  # noqa: WPS301
+from importlib import import_module
+from contextlib import suppress
 
 from . import server
 from . import wsgi
-from ._compat import suppress
-
-
-__metaclass__ = type
 
 
 class BindLocation:
@@ -143,7 +139,7 @@ def parse_wsgi_bind_location(bind_addr_string):
         return AbstractSocket(bind_addr_string[1:])
 
     # try and match for an IP/hostname and port
-    match = six.moves.urllib.parse.urlparse(
+    match = urllib.parse.urlparse(
         '//{addr}'.format(addr=bind_addr_string),
     )
     try:

cheroot/connections.py

@@ -1,22 +1,17 @@
 """Utilities to manage open connections."""
 
-from __future__ import absolute_import, division, print_function
-__metaclass__ = type
-
 import io
 import os
 import socket
 import threading
 import time
+import selectors
+from contextlib import suppress
 
 from . import errors
-from ._compat import selectors
-from ._compat import suppress
 from ._compat import IS_WINDOWS
 from .makefile import MakeFile
 
-import six
-
 try:
     import fcntl
 except ImportError:
@@ -310,8 +305,7 @@ def _from_server_socket(self, server_socket):  # noqa: C901  # FIXME
                         msg,
                     ]
 
-                    sock_to_make = s if not six.PY2 else s._sock
-                    wfile = mf(sock_to_make, 'wb', io.DEFAULT_BUFFER_SIZE)
+                    wfile = mf(s, 'wb', io.DEFAULT_BUFFER_SIZE)
                     try:
                         wfile.write(''.join(buf).encode('ISO-8859-1'))
                     except socket.error as ex:
@@ -327,10 +321,7 @@ def _from_server_socket(self, server_socket):  # noqa: C901  # FIXME
 
             conn = self.server.ConnectionClass(self.server, s, mf)
 
-            if not isinstance(
-                    self.server.bind_addr,
-                    (six.text_type, six.binary_type),
-            ):
+            if not isinstance(self.server.bind_addr, (str, bytes)):
                 # optional values
                 # Until we do DNS lookups, omit REMOTE_HOST
                 if addr is None:  # sometimes this can happen

cheroot/errors.py

@@ -1,9 +1,6 @@
 # -*- coding: utf-8 -*-
 """Collection of exceptions raised and/or processed by Cheroot."""
 
-from __future__ import absolute_import, division, print_function
-__metaclass__ = type
-
 import errno
 import sys