This document discusses how to build GUIs using PyQt by drawing the problem, choosing appropriate widgets, building a simple form using PyQt's class hierarchy and signals/slots, adding CSS for aesthetics, and distributing the application by packaging it into an .exe file. It covers understanding PyQt's classes for UI elements and behaviors, connecting widgets to functions via signals and slots, using QtDesigner for a WYSIWYG editor, and libraries for freezing Python into executables.

1. How to approach building
GUIs using PyQt
Jerlyn Manohar

2. Summary:
● Draw your problem
● Know your widgets: choosing the right widget for the job
● Building a simple PyQT form: understanding PyQT’s class hierarchy,
inheritance, and Signals/Slots
● GUI, but make it aesthetically pleasing: adding CSS to your application
● Distributing your application: Packaging the scripts as .exe and distributing
them to client machines
● Q/A

3. Introduction
Desktop applications are a GREAT idea if:
● Your user base only uses one platform
● You want to view/study/analyze device content
● You want to let people interact with sensitive data, but are worried about
external penetration
● Your users don’t rely on internet connectivity to perform their work
● Etc...

4. So, you’ve decided that a native desktop app fits
your business purpose better. What’s next?
Draw your problem

6. Draw -
● How you want the user to interact with the ‘ingredients’ of your app
● What the user should not be doing
● What the reward for a successful interaction is
Let’s try building a simple form.

8. Understanding how PyQt works beneath the
hood
● PyQT has several classes
● QtGui to initialize UI elements, QtCore to define/edit behavior of the UI
elements, QtDesigner to generate a .ui file, uic to convert .ui to .py files, etc
● A QApplication is the main app
● Let's convert our drawing into an application

9. You now have a form...how can a user
meaningfully interact with it now?
● By connecting widgets to functions
● These can be established through establishing signals and slots connections
using the widgets’ in-built methods
● Put it this way: a signal is the switch being pressed, the slot is the electrical
wiring that connects it to the fan, and the function is the fan turning on
● The different signal/slot connections can be studied from the official docs

10. However, the discussed isn't the 'only’ way to
create PyQt UI elements
● You can use the QtDesigner application that ships with PyQt4/5 .whl for
windows
● If you're on Linux/OSX you might have to search for and download the
compiled version or do it yourself
● QtDesigner is a wysiwyg UI editor that generates .ui files
● You can load the .ui file into your main python program by using uic and its
loadUi method
● Or, use pyuic to convert the .ui file into a python file

11. You can also add CSS to the widgets
● Either directly from the QtDesigner
● Or, using the setStylesheet method of each QWidget

12. Distributing your application
● Use “freeze” method to package your application for distribution to client
systems
● For windows, you can convert .py to .exe with all the necessary windows .dlls,
any custom python modules, etc
● Some libraries to help you do it are py2exe, cxfreeze, PyInstaller, etc.

13. For further questions/assistance:
● Mail me at jerlynmanohar@gmail.com
● Find me on LinkedIn at
https://www.linkedin.com/in/jerlyn-manohar-605649101/