Support triple backticks for code blocks

 
     """
 
-    pattern = r"^[ ]{4}"
+    pattern = r"^([ ]{4}|`{3})"
 
     def parse(self, block):
         """"""
+        if block.lstrip().startswith("```") and block.rstrip().endswith("```"):
+            block = block.lstrip().rstrip()[3:-3]
         text = dedent(block)
         if text.startswith(">>> "):
             lexer = pygments.lexers.PythonConsoleLexer()