Partial py3k-ification of Doc/library/: convert has_key references into either 'k in d' or __contains__; normalize raise statements; convert print statements into print function calls.
diff --git a/Doc/library/mailbox.rst b/Doc/library/mailbox.rst
index ce8dc59..cfd1ebe 100644
--- a/Doc/library/mailbox.rst
+++ b/Doc/library/mailbox.rst
@@ -188,8 +188,7 @@
subclass.
-.. method:: Mailbox.has_key(key)
- Mailbox.__contains__(key)
+.. method:: Mailbox.__contains__(key)
Return ``True`` if *key* corresponds to a message, ``False`` otherwise.