Rapid GUI Programming with Python and Qt: The Definitive Guide to PyQt Programming

19. Multithreading

• Creating a Threaded Server
• Creating and Managing Secondary Threads
• Implementing a Secondary Thread

Traditionally, applications have a single thread of execution and perform one operation at a time. For GUI programs this can sometimes be a problem—for example, if the user invokes a long-running operation, the user interface might freeze up while the operation is taking place. There are a few solutions that can be tried to eliminate this problem.

One simple solution, particularly useful in long-running loops, is to call QApplication.processEvents(). This method gives the event loop the opportunity to handle any unprocessed events, such as paint events, as well as mouse and key press events.Another solution is to use zero-timeout ...