Add on_error event for doing something about uncaught exceptions.

discord/client.py

@@ -38,7 +38,7 @@ import json, re, time, copy
 from collections import deque
 from threading import Timer
 from ws4py.client.threadedclient import WebSocketClient
-from sys import platform as sys_platform
+import sys
 
 def _null_event(*args, **kwargs):
     pass
@@ -197,7 +197,8 @@ class Client(object):
         try:
             self.events[event_name](*args, **kwargs)
         except Exception as e:
-            pass
+            self.events['error'](event_name, *sys.exc_info())
+
 
     def _received_message(self, msg):
         response = json.loads(str(msg))
@@ -511,7 +512,7 @@ class Client(object):
                 'd': {
                     'token': self.token,
                     'properties': {
-                        '$os': sys_platform,
+                        '$os': sys.platform,
                         '$browser': 'discord.py',
                         '$device': 'discord.py',
                         '$referrer': '',

docs/api.rst

@@ -30,6 +30,19 @@ All events are 'sandboxed', in that if an exception is thrown while the event is
 
     Called when the client disconnects for whatever reason. Be it error or manually.
 
+.. function:: on_error(event, type, value, traceback)
+
+    Usually when an event throws an uncaught exception, it is swallowed. If you want to handle
+    the uncaught exceptions for whatever reason, this event is called. If an exception is thrown
+    on this event then it propagates (i.e. it is not swallowed silently).
+
+    The parameters for this event are retrieved through the use of ``sys.exc_info()``.
+
+    :param event: The event name that had the uncaught exception.
+    :param type: The type of exception that was swallowed.
+    :param value: The actual exception that was swallowed.
+    :param traceback: The traceback object representing the traceback of the exception swallowed.
+
 .. function:: on_message(message)
 
     Called when a message is created and sent to a server.