refactor: replace print statements with logging for better error handling

Author: Paillat-dev

discord/__main__.py

@@ -25,6 +25,7 @@
 
 import argparse
 import importlib.metadata
+import logging
 import platform
 import sys
 from pathlib import Path
@@ -34,6 +35,7 @@
 
 import discord
 
+_log = logging.getLogger(__name__)
 
 def show_version() -> None:
     entries = [
@@ -239,7 +241,7 @@ def newbot(parser, args) -> None:
         init = cogs / "__init__.py"
         init.touch()
     except OSError as exc:
-        print(f"warning: could not create cogs directory ({exc})")
+        _log.exception(f"Could not create cogs directory.")
 
     try:
         with open(str(new_directory / "config.py"), "w", encoding="utf-8") as fp:
@@ -259,17 +261,17 @@ def newbot(parser, args) -> None:
             with open(str(new_directory / ".gitignore"), "w", encoding="utf-8") as fp:
                 fp.write(_gitignore_template)
         except OSError as exc:
-            print(f"warning: could not create .gitignore file ({exc})")
+            _log.exception(f"Could not create .gitignore file.")
 
-    print("successfully made bot at", new_directory)
+    print("Successfully made bot at", new_directory)
 
 
 def newcog(parser, args) -> None:
     cog_dir = to_path(parser, args.directory)
     try:
         cog_dir.mkdir(exist_ok=True)
     except OSError as exc:
-        print(f"warning: could not create cogs directory ({exc})")
+        _log.exception(f"Could not create cogs directory.")
 
     directory = cog_dir / to_path(parser, args.name)
     directory = directory.with_suffix(".py")

discord/bot.py

@@ -1240,7 +1240,7 @@ async def on_application_command_error(
 
         The default command error handler provided by the bot.
 
-        By default, this prints to :data:`sys.stderr` however it could be
+        By default, this logs with :meth:`logging.exception` however it could be
         overridden to have a different implementation.
 
         This only fires if you do not specify any listeners for command error.
@@ -1255,10 +1255,7 @@ async def on_application_command_error(
         if cog and cog.has_error_handler():
             return
 
-        print(f"Ignoring exception in command {context.command}:", file=sys.stderr)
-        traceback.print_exception(
-            type(exception), exception, exception.__traceback__, file=sys.stderr
-        )
+        _log.error(f"Ignoring exception in command {context.command}.", exc_info=exception)
 
     # global check registration
     # TODO: Remove these from commands.Bot

discord/client.py

@@ -536,11 +536,11 @@ async def on_error(self, event_method: str, *args: Any, **kwargs: Any) -> None:
 
         The default error handler provided by the client.
 
-        By default, this prints to :data:`sys.stderr` however it could be
+        By default, this logs with :meth:`logging.error` however it could be
         overridden to have a different implementation.
         Check :func:`~discord.on_error` for more details.
         """
-        print(f"Ignoring exception in {event_method}", file=sys.stderr)
+        _log.error(f"Ignoring exception in {event_method}")
         traceback.print_exc()
 
     async def on_view_error(
@@ -553,27 +553,22 @@ async def on_view_error(
         This only fires for a view if you did not define its :func:`~discord.ui.View.on_error`.
         """
 
-        print(
+        _log.error(
             f"Ignoring exception in view {interaction.view} for item {item}:",
-            file=sys.stderr,
-        )
-        traceback.print_exception(
-            error.__class__, error, error.__traceback__, file=sys.stderr
+            exc_info=error,
         )
 
     async def on_modal_error(self, error: Exception, interaction: Interaction) -> None:
         """|coro|
 
         The default modal error handler provided by the client.
-        The default implementation prints the traceback to stderr.
+        The default implementation logs the traceback with :meth:`logging.error`.
 
         This only fires for a modal if you did not define its :func:`~discord.ui.Modal.on_error`.
         """
 
-        print(f"Ignoring exception in modal {interaction.modal}:", file=sys.stderr)
-        traceback.print_exception(
-            error.__class__, error, error.__traceback__, file=sys.stderr
-        )
+        _log.error(f"Ignoring exception in modal {interaction.modal}", exc_info=error)
+
 
     # hooks
 

discord/ext/commands/bot.py

@@ -28,6 +28,7 @@
 import collections
 import collections.abc
 import sys
+import logging
 import traceback
 from typing import TYPE_CHECKING, Any, Callable, Coroutine, Iterable, TypeVar
 
@@ -51,6 +52,8 @@
     "AutoShardedBot",
 )
 
+_log = logging.getLogger(__name__)
+
 MISSING: Any = discord.utils.MISSING
 
 T = TypeVar("T")
@@ -156,7 +159,7 @@ async def on_command_error(
 
         The default command error handler provided by the bot.
 
-        By default, this prints to :data:`sys.stderr` however it could be
+        By default, this logs with :meth:`logging.error` however it could be
         overridden to have a different implementation.
 
         This only fires if you do not specify any listeners for command error.
@@ -172,10 +175,7 @@ async def on_command_error(
         if cog and cog.has_error_handler():
             return
 
-        print(f"Ignoring exception in command {context.command}:", file=sys.stderr)
-        traceback.print_exception(
-            type(exception), exception, exception.__traceback__, file=sys.stderr
-        )
+        logging.error(f"Ignoring exception in command {context.command}", exc_info=exception)
 
     async def can_run(self, ctx: Context, *, call_once: bool = False) -> bool:
         data = self._check_once if call_once else self._checks

discord/ext/tasks/__init__.py

@@ -29,6 +29,7 @@
 import datetime
 import inspect
 import sys
+import logging
 import traceback
 from collections.abc import Sequence
 from typing import Any, Awaitable, Callable, Generic, TypeVar, cast
@@ -47,6 +48,7 @@
 FT = TypeVar("FT", bound=_func)
 ET = TypeVar("ET", bound=Callable[[Any, BaseException], Awaitable[Any]])
 
+_log = logging.getLogger(__name__)
 
 class SleepHandle:
     __slots__ = ("future", "loop", "handle")
@@ -474,12 +476,9 @@ def is_running(self) -> bool:
 
     async def _error(self, *args: Any) -> None:
         exception: Exception = args[-1]
-        print(
+        _log.error(
             f"Unhandled exception in internal background task {self.coro.__name__!r}.",
-            file=sys.stderr,
-        )
-        traceback.print_exception(
-            type(exception), exception, exception.__traceback__, file=sys.stderr
+            exc_info=exception,
         )
 
     def before_loop(self, coro: FT) -> FT:
@@ -544,7 +543,7 @@ def error(self, coro: ET) -> ET:
 
         The coroutine must take only one argument the exception raised (except ``self`` in a class context).
 
-        By default, this prints to :data:`sys.stderr` however it could be
+        By default, this logs with the logging module however it could be
         overridden to have a different implementation.
 
         .. versionadded:: 1.4

discord/opus.py

@@ -550,7 +550,7 @@ def run(self):
                         data.decrypted_data
                     )
             except OpusError:
-                print("Error occurred while decoding opus frame.")
+                _log.exception("Error occurred while decoding opus frame.")
                 continue
 
             self.client.recv_decoded_audio(data)
@@ -560,7 +560,7 @@ def stop(self):
             time.sleep(0.1)
             self.decoder = {}
             gc.collect()
-            print("Decoder Process Killed")
+            _log.info("Decoder Process Killed")
         self._end_thread.set()
 
     def get_decoder(self, ssrc):

discord/player.py

@@ -808,8 +808,6 @@ def _call_after(self) -> None:
         elif error:
             msg = f"Exception in voice thread {self.name}"
             _log.exception(msg, exc_info=error)
-            print(msg, file=sys.stderr)
-            traceback.print_exception(type(error), error, error.__traceback__)
 
     def stop(self) -> None:
         self._end.set()

discord/ui/modal.py

@@ -259,7 +259,7 @@ async def on_error(self, error: Exception, interaction: Interaction) -> None:
 
         A callback that is called when the modal's callback fails with an error.
 
-        The default implementation prints the traceback to stderr.
+        The default implementation logs the traceback with the logging module.
 
         Parameters
         ----------

discord/ui/view.py

@@ -520,7 +520,7 @@ async def on_error(
         A callback that is called when an item's callback or :meth:`interaction_check`
         fails with an error.
 
-        The default implementation prints the traceback to stderr.
+        The default implementation logs the traceback with the logging module.
 
         Parameters
         ----------

discord/voice_client.py

@@ -852,7 +852,7 @@ def recv_audio(self, sink, callback, *args):
             ready, _, err = select.select([self.socket], [], [self.socket], 0.01)
             if not ready:
                 if err:
-                    print(f"Socket error: {err}")
+                    _log.error(f"Socket error: {err}")
                 continue
 
             try:
@@ -869,7 +869,7 @@ def recv_audio(self, sink, callback, *args):
         result = callback.result()
 
         if result is not None:
-            print(result)
+            _log.info(result)
 
     def recv_decoded_audio(self, data: RawData):
         # Add silence when they were not being recorded.