=== modified file 'lisp/progmodes/python.el'
--- lisp/progmodes/python.el	2012-10-07 19:37:37 +0000
+++ lisp/progmodes/python.el	2012-10-07 19:47:52 +0000
@@ -1887,7 +1887,9 @@
    python-shell-output-filter-buffer
    (concat python-shell-output-filter-buffer string))
   (when (string-match
-         (format "\n\\(?:%s\\|%s\\|%s\\)$"
+         ;; It seems on OSX an extra carriage return might be attached
+         ;; to the end of output.
+         (format "
?\n\\(?:%s\\|%s\\|%s\\)$"
                  python-shell-prompt-regexp
                  python-shell-prompt-block-regexp
                  python-shell-prompt-pdb-regexp)