#Graphical User Interface (GUI)

Before this, the program interfaces we developed were all text-based interfaces:

planc@dev:~$ python main.py
hello world

Whereas most applications on modern personal computers have graphical user interfaces like this:

Implementing a graphical interface requires rendering, and since multiple applications need to coordinate, the actual rendering operations are handled by the operating system.

Application developers usually only need to call interfaces provided by the operating system, but directly calling system interfaces can still be cumbersome. Therefore, third-party libraries are commonly used to simplify application development.

There are many third-party GUI libraries for Python, such as Tkinter, wxWidgets, Qt, and GTK. Among them, Qt is the most practical.