I tried to use the quickly.widgets.text_editor class in a quickly project just now (as in one of the highlighted quickly tutorials) and got an import error. When I tried to inspect the quickly.widgets module I got an import error. Does quickly still include its own widgets? Does it still include the text_editor widget? There doesn't seem to be any coherent API documentation for quickly on the Ubuntu developers site! (Sorry if I'm just missing something obvious.) Thanks.
Sounds like you maybe don't have the quickly-widgets package installed.
Then, e.g. following this video http://www.youtube.com/watch?v=urwBBlYhaUU&feature=player_embedded, the imports seems to work fine.
As far as docs go, the best I could find is using pythons internal documentation system.