Python PyQt Desktop Apps — ELI5

Picture two ways to build a toy house. You could grab some cardboard and tape — quick and easy, but it looks homemade. Or you could open a professional LEGO set with hundreds of special pieces: windows that slide, doors with hinges, even tiny working lights. The house takes longer to build, but it looks and feels like a real one.

PyQt is the professional LEGO set for making desktop programs with Python. It wraps a giant toolkit called Qt (pronounced “cute”) that companies use to build real software you probably already have on your computer — VLC media player, the Calibre ebook manager, and parts of Dropbox all use Qt.

When you build with PyQt, you get pre-made pieces for almost anything: buttons, tables, file pickers, menus, toolbars, tabs, sliders, calendars, even a built-in web browser widget. Each piece already looks right on Windows, macOS, and Linux because Qt adapts to whatever system your program runs on.

Here is how it works. You create a window, then fill it with those ready-made pieces. You tell each piece what to do when someone interacts with it — click this button and it saves a file, type in this box and it searches a list. Then you start a loop that keeps the window alive and listening.

The only catch is that PyQt does not come built into Python. You need to install it first, like downloading the LEGO set before you can build. But once you have it, you can make apps that look just as polished as anything written in C++ or Java.

One thing to remember: PyQt gives Python access to the same professional-grade widgets and styling used by major desktop applications, on every operating system.