PyQt5 create multi-threaded

See also:

https://blog.csdn.net/chengmo123/article/details/96477103

https://www.cnblogs.com/zhuminghui/p/9507982.html

The latter describes how to generate a thread

The former introduced (under thread to give birth in the original object should be self pyqt5 in) some of the problems that may arise generate thread