Is it possible to include an external stylesheet for a PyQt4 application?

Question

Python

As you know, styles can be attached to individual elements in PyQt via setStyleSheet, similar to css.
For example:

self.button.setStyleSheet("font-size:40px;background-color:#333333;\
        border: 2px solid #222222")

This is done either in Qt Designer, or already in the .py file. It's all simple and clear.
There was a question which consists of two:
1 Is it possible to include an external style file directly in Qt Designer?
2 If this is not possible, then maybe there is a possibility to include the style file in the .py file?
I saw that it is possible to do this in C ++ (connecting an external .qss style file). Therefore, the question arose.
As a result, I want to take out the design of the application on PyQt in a separate file.

Answer 1

Finally found a simple and working example - https://github.com/jangelo/pyqt-helloworld .
Normal window:
The same window with an external stylesheet attached: