My question is not specific to Python/PyQt4 but it's the language and api I'm currently using. I want to know if there is a library to automatically generate GUI forms from public parameters of an object. It would be very useful for automatic settings generation.
There is no need for searching fully suited library. Also, i think, it is unnecessary and waste of time. There are lots of frustrating issue, such as localization settings, number format settings, validation issue etc.
I recommend, use Qt designer form layout to create quickly a form. 
Then use pyqt4/QValidation and u can use some regular expression(python new regex module better than QRegExp).
At the and of, manage custom objects via jsonpickle or just python pickle.
Best practice to generate the settings view of an UI