Add guessing game example to showcase wait_for_message.

examples/guessing_game.py

@@ -0,0 +1,37 @@
+import discord
+import random
+
+client = discord.Client()
+
+@client.async_event
+def on_message(message):
+    # we do not want the bot to reply to itself
+    if message.author == client.user:
+        return
+
+    if message.content.startswith('$guess'):
+        yield from client.send_message(message.channel, 'Guess a number between 1 to 10')
+
+        def guess_check(m):
+            return m.content.isdigit()
+
+        guess = yield from client.wait_for_message(timeout=5.0, author=message.author, check=guess_check)
+        answer = random.randint(1, 10)
+        if guess is None:
+            fmt = 'Sorry, you took too long. It was {}.'
+            yield from client.send_message(message.channel, fmt.format(answer))
+            return
+        if int(guess.content) == answer:
+            yield from client.send_message(message.channel, 'You are right!')
+        else:
+            yield from client.send_message(message.channel, 'Sorry. It is actually {}.'.format(answer))
+
+
+@client.async_event
+def on_ready():
+    print('Logged in as')
+    print(client.user.name)
+    print(client.user.id)
+    print('------')
+
+client.run('email', 'password')