Difference between qt and PyQt4

Well I am new to Qt and found its easier to work with python , I dont know how far its true . but some of the code snippets have

 import qt 

and some have

 import PyQt4 

I don't know what the difference is, when I tried to interchange them I did get some errors , like some function was not recognizable and so on, 开发者_运维百科also I am trying to build front end GUI for my application, which GUI framework would u suggest ? Is there anything close to VB like environment ?

Old PyQt3 use qt

import qt

Current PyQt4 use PyQt4

import PyQt4

If you use PySide, use PySide

import PySide