Raise Minimum Python Version to 3.8 (#1597)

* raise minimum python version to 3.8

* try to fix entry points

* use walrus and hasattr

* update supported versions

Author: zariiii9003

.github/workflows/ci.yml

@@ -18,12 +18,10 @@ jobs:
         os: [ubuntu-latest, macos-latest, windows-latest]
         experimental: [false]
         python-version: [
-          "3.7",
           "3.8",
           "3.9",
           "3.10",
           "3.11",
-          "pypy-3.7",
           "pypy-3.8",
           "pypy-3.9",
         ]
@@ -85,9 +83,6 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install -e .[lint]
-    - name: mypy 3.7
-      run: |
-        mypy --python-version 3.7 .
     - name: mypy 3.8
       run: |
         mypy --python-version 3.8 .

README.rst

@@ -62,7 +62,8 @@ Library Version                 Python
 ------------------------------  -----------
   2.x                           2.6+, 3.4+
   3.x                           2.7+, 3.5+
-  4.x                           3.7+
+  4.0+                          3.7+
+  4.3+                          3.8+
 ==============================  ===========
 
 

can/__init__.py

@@ -61,6 +61,7 @@
     "exceptions",
     "interface",
     "interfaces",
+    "io",
     "listener",
     "logconvert",
     "log",

can/_entry_points.py

@@ -0,0 +1,34 @@
+import importlib
+import sys
+from dataclasses import dataclass
+from importlib.metadata import entry_points
+from typing import Any, List
+
+
+@dataclass
+class _EntryPoint:
+    key: str
+    module_name: str
+    class_name: str
+
+    def load(self) -> Any:
+        module = importlib.import_module(self.module_name)
+        return getattr(module, self.class_name)
+
+
+# See https://docs.python.org/3/library/importlib.metadata.html#entry-points,
+# "Compatibility Note".
+if sys.version_info >= (3, 10):
+
+    def read_entry_points(group: str) -> List[_EntryPoint]:
+        return [
+            _EntryPoint(ep.name, ep.module, ep.attr) for ep in entry_points(group=group)
+        ]
+
+else:
+
+    def read_entry_points(group: str) -> List[_EntryPoint]:
+        return [
+            _EntryPoint(ep.name, *ep.value.split(":", maxsplit=1))
+            for ep in entry_points().get(group, [])
+        ]

can/broadcastmanager.py

@@ -10,9 +10,7 @@
 import sys
 import threading
 import time
-from typing import TYPE_CHECKING, Callable, Optional, Sequence, Tuple, Union
-
-from typing_extensions import Final
+from typing import TYPE_CHECKING, Callable, Final, Optional, Sequence, Tuple, Union
 
 from can import typechecking
 from can.message import Message

can/bus.py

@@ -8,7 +8,21 @@
 from abc import ABC, ABCMeta, abstractmethod
 from enum import Enum, auto
 from time import time
-from typing import Any, Callable, Iterator, List, Optional, Sequence, Tuple, Union, cast
+from types import TracebackType
+from typing import (
+    Any,
+    Callable,
+    Iterator,
+    List,
+    Optional,
+    Sequence,
+    Tuple,
+    Type,
+    Union,
+    cast,
+)
+
+from typing_extensions import Self
 
 import can
 import can.typechecking
@@ -450,10 +464,15 @@ def shutdown(self) -> None:
         self._is_shutdown = True
         self.stop_all_periodic_tasks()
 
-    def __enter__(self):
+    def __enter__(self) -> Self:
         return self
 
-    def __exit__(self, exc_type, exc_val, exc_tb):
+    def __exit__(
+        self,
+        exc_type: Optional[Type[BaseException]],
+        exc_value: Optional[BaseException],
+        traceback: Optional[TracebackType],
+    ) -> None:
         self.shutdown()
 
     def __del__(self) -> None:

can/interfaces/__init__.py

@@ -2,8 +2,9 @@
 Interfaces contain low level implementations that interact with CAN hardware.
 """
 
-import sys
-from typing import Dict, Tuple, cast
+from typing import Dict, Tuple
+
+from can._entry_points import read_entry_points
 
 __all__ = [
     "BACKENDS",
@@ -60,36 +61,12 @@
     "socketcand": ("can.interfaces.socketcand", "SocketCanDaemonBus"),
 }
 
-if sys.version_info >= (3, 8):
-    from importlib.metadata import entry_points
-
-    # See https://docs.python.org/3/library/importlib.metadata.html#entry-points,
-    # "Compatibility Note".
-    if sys.version_info >= (3, 10):
-        BACKENDS.update(
-            {
-                interface.name: (interface.module, interface.attr)
-                for interface in entry_points(group="can.interface")
-            }
-        )
-    else:
-        # The entry_points().get(...) causes a deprecation warning on Python >= 3.10.
-        BACKENDS.update(
-            {
-                interface.name: cast(
-                    Tuple[str, str], tuple(interface.value.split(":", maxsplit=1))
-                )
-                for interface in entry_points().get("can.interface", [])
-            }
-        )
-else:
-    from pkg_resources import iter_entry_points
 
-    BACKENDS.update(
-        {
-            interface.name: (interface.module_name, interface.attrs[0])
-            for interface in iter_entry_points("can.interface")
-        }
-    )
+BACKENDS.update(
+    {
+        interface.key: (interface.module_name, interface.class_name)
+        for interface in read_entry_points(group="can.interface")
+    }
+)
 
-VALID_INTERFACES = frozenset(BACKENDS.keys())
+VALID_INTERFACES = frozenset(sorted(BACKENDS.keys()))

can/io/generic.py

@@ -8,14 +8,15 @@
     BinaryIO,
     ContextManager,
     Iterable,
+    Literal,
     Optional,
     TextIO,
     Type,
     Union,
     cast,
 )
 
-from typing_extensions import Literal
+from typing_extensions import Self
 
 from .. import typechecking
 from ..listener import Listener
@@ -65,7 +66,7 @@ def __init__(
         # for multiple inheritance
         super().__init__()
 
-    def __enter__(self) -> "BaseIOHandler":
+    def __enter__(self) -> Self:
         return self
 
     def __exit__(

can/io/logger.py

@@ -8,11 +8,11 @@
 from abc import ABC, abstractmethod
 from datetime import datetime
 from types import TracebackType
-from typing import Any, Callable, Dict, Optional, Set, Tuple, Type, cast
+from typing import Any, Callable, Dict, Literal, Optional, Set, Tuple, Type, cast
 
-from pkg_resources import iter_entry_points
-from typing_extensions import Literal
+from typing_extensions import Self
 
+from .._entry_points import read_entry_points
 from ..listener import Listener
 from ..message import Message
 from ..typechecking import AcceptedIOType, FileLike, StringPathLike
@@ -89,8 +89,8 @@ def __new__(  # type: ignore
         if not Logger.fetched_plugins:
             Logger.message_writers.update(
                 {
-                    writer.name: writer.load()
-                    for writer in iter_entry_points("can.io.message_writer")
+                    writer.key: cast(Type[MessageWriter], writer.load())
+                    for writer in read_entry_points("can.io.message_writer")
                 }
             )
             Logger.fetched_plugins = True
@@ -99,19 +99,19 @@ def __new__(  # type: ignore
 
         file_or_filename: AcceptedIOType = filename
         if suffix == ".gz":
-            LoggerType, file_or_filename = Logger.compress(filename, **kwargs)
+            logger_type, file_or_filename = Logger.compress(filename, **kwargs)
         else:
-            LoggerType = cls._get_logger_for_suffix(suffix)
+            logger_type = cls._get_logger_for_suffix(suffix)
 
-        return LoggerType(file=file_or_filename, **kwargs)
+        return logger_type(file=file_or_filename, **kwargs)
 
     @classmethod
     def _get_logger_for_suffix(cls, suffix: str) -> Type[MessageWriter]:
         try:
-            LoggerType = Logger.message_writers[suffix]
-            if LoggerType is None:
+            logger_type = Logger.message_writers[suffix]
+            if logger_type is None:
                 raise ValueError(f'failed to import logger for extension "{suffix}"')
-            return LoggerType
+            return logger_type
         except KeyError:
             raise ValueError(
                 f'No write support for this unknown log format "{suffix}"'
@@ -130,15 +130,15 @@ def compress(
             raise ValueError(
                 f"The file type {real_suffix} is currently incompatible with gzip."
             )
-        LoggerType = cls._get_logger_for_suffix(real_suffix)
+        logger_type = cls._get_logger_for_suffix(real_suffix)
         append = kwargs.get("append", False)
 
-        if issubclass(LoggerType, BinaryIOMessageWriter):
+        if issubclass(logger_type, BinaryIOMessageWriter):
             mode = "ab" if append else "wb"
         else:
             mode = "at" if append else "wt"
 
-        return LoggerType, gzip.open(filename, mode)
+        return logger_type, gzip.open(filename, mode)
 
     def on_message_received(self, msg: Message) -> None:
         pass
@@ -275,7 +275,7 @@ def stop(self) -> None:
         """
         self.writer.stop()
 
-    def __enter__(self) -> "BaseRotatingLogger":
+    def __enter__(self) -> Self:
         return self
 
     def __exit__(