Werkzeug originally had a magical import system hook that enabled everything to be imported from one module and still loading the actual implementations lazily as necessary. Unfortunately this turned out to be slow and also unreliable on alternative Python implementations and Google’s App Engine.
Starting with 0.7 we recommend against the short imports and strongly encourage starting importing from the actual implementation module. Werkzeug 1.0 will disable the magical import hook completely.
Because finding out where the actual functions are imported and rewriting them by hand is a painful and boring process we wrote a tool that aids in making this transition.