Run nosetests from any directory in your virtualenv (Windows compatible)

nosetmacs.el

(defun run-tests ()
  "Finds the virtualenv bin-dir and run nosetests"
  (interactive)
  (let ((bin-dir (if (eq system-type 'windows-nt) "Scripts" "bin"))
	(cwd (reverse (split-string default-directory "/"))))
    (let ((venv-dir (if (string= (first cwd) "")
			(find-bin-dir (rest cwd) bin-dir)
		      (find-bin-dir cwd bin-dir))))
      (if venv-dir
	  (let ((old-path (getenv "PATH")))
	    (setenv "PATH" (concat venv-dir ";" old-path))
	    (compile "nosetests")
	    (setenv old-path))
	(message "Virtualenv not found")))))

(defun find-bin-dir (path target)
  "Move up the dir tree looking for a virtualenv bin-dir"
  (let ((test-path 
	 (mapconcat 'identity (append (reverse path) (list target)) "/")))
    (if (file-exists-p test-path)
	test-path
      (if (not (eq (rest path) nil))
	  (find-bin-dir (rest path) target)
	nil))))