Clearer error on send_file(chat, invalid type)

telethon/client/uploads.py

@@ -184,6 +184,10 @@ class UploadMethods(ButtonMethods, MessageParseMethods, UserMethods):
             The `telethon.tl.custom.message.Message` (or messages) containing
             the sent file, or messages if a list of them was passed.
         """
+        # i.e. ``None`` was used
+        if not file:
+            raise TypeError('Cannot use {!r} as file'.format(file))
+
         if not caption:
             caption = ''
 
@@ -243,6 +247,10 @@ class UploadMethods(ButtonMethods, MessageParseMethods, UserMethods):
             supports_streaming=supports_streaming
         )
 
+        # e.g. invalid cast from :tl:`MessageMediaWebPage`
+        if not media:
+            raise TypeError('Cannot use {!r} as file'.format(file))
+
         markup = self.build_reply_markup(buttons)
         request = functions.messages.SendMediaRequest(
             entity, media, reply_to_msg_id=reply_to, message=caption,

telethon_examples/assistant.py

@@ -313,7 +313,7 @@ async def handler(event):
     text = 'Available commands:\n'
     for callback, handler in bot.list_event_handlers():
         if isinstance(handler, events.NewMessage) and callback.__doc__:
-            text += f'\n{callback.__doc__}'
+            text += f'\n{callback.__doc__.strip()}'
     text += '\n\nYou can suggest new commands [here](https://docs.google.com/'\
             'spreadsheets/d/12yWwixUu_vB426_toLBAiajXxYKvR2J1DD6yZtQz9l4/edit).'