Qt for Python

General Introduction

For internal and external distribution

Naming

Qt for Python is the global name of the project.

PySide
- Python bindings for most Qt API
Shiboken Generator
- Binary to generate bindings
Shiboken Module
- Python helper module
Others
- Shiboken Wizard
- QtCreator integration

The story of PySide

2008

Qt4
Development
(PySide)

2016

Back
to the
Qt Project

2015

Qt5
Port
(PySide6)

2018

Released
(Qt for Python)

Release information

Qt for Python (Qt 5.11) - Technical Preview
Qt for Python (Qt 5.12) - Official Release
Releases follow the Qt releases

Qt5 latest is 5.15.2 OSS and 5.15.12 Commercial LTS
Qt6 latest is 6.4.2 OSS and 6.2.7 Commercial LTS

(Slide updated on 14.02.2023)

Python Compatibility

PySide2 (5.15)
- Python 2.7
- Python 3.6 or greater
PySide6 (6.x)
- Python 3.6+ is required for 6.0, 6.1, 6.2 and 6.3
- Python 3.7+ is required for 6.4+

License (1/3)

LGPLv3/GPLv3 for Community users (OSS)
- The tools we included are GPLv3
  pyside6-uic, pyside6-rcc, pyside6-designer etc.
- shiboken_generator is GPLv3
- Qt libraries licenses depend on the module
  (*.so, *.dll, *.dylib)
- Everything else is LGPLv3

License (2/3)

Commercial features included in the
"Qt for Application Development Professional".
- Community content
- LTS releases
- Shiboken Wizard

License (3/3)

Commercial features included in the
"Qt for Application Development Enterprise" onward.
- AD Professional content
- Only 3 modules from the Qt M2M (previously Qt for Automation) Protocols
  (QtOpcUa, QtMqtt, QtCoAp)

Setup 🔨

Installation (1/3)

Installing Qt doesn't include Qt for Python
- Not listed on the Qt Maintenance Tool (*)
- Only allowed via account.qt.io

(*) Work is being done to include it.

Installation (2/3)

Qt for Python is distributed via Python Packages (.whl files)
- The official Python interpreter is supported - python.org
- The official PyPy interpreter is supported - pypy.org
- conda is supported(starting from 6.4.3) - anaconda.com
Distribution via Python Package Index is supported (only for OSS users)- pypi.org

Installation (3/3)

Community (OSS) and Commercial installations are different processes.

Community Edition (OSS)

How to install

Community Edition (OSS)

What is installed?


     ▪️PySide6
      ├── Qt modules              ✅
      ├── pyside6-designer        ✅
      ├── pyside6-rcc             ✅
      ├── pyside6-uic             ✅
      └── ...tools                ✅
     ▪️Shiboken6 (module)
      └── shiboken6               ✅
     ▪️Shiboken6_Generator (exe)
      └── shiboken6               ❌

Community Edition (OSS)

Installing `shiboken_generator`

Build from source - code.qt.io/cgit/pyside/pyside-setup.git
Get the wheel snapshots - download.qt.io/snapshots/ci/pyside/

The main issue for not having it public is the dependency with libclang.

Community Edition (OSS)

Installing Shiboken Generator

the simple way


    pip install \
        --index-url=http://download.qt.io/official_releases/QtForPython/ \
        --trusted-host download.qt.io \
        shiboken6 pyside6 shiboken6_generator

But one needs to:

Set CLANG_INSTALL_DIR to the libclang directory
Add to PATH a Qt bin path with the same version
Add to LD_LIBRARY_PATH the Qt lib path with the same version

Community Edition (OSS)

Installing Shiboken Generator

the hard way?

Set CLANG_INSTALL_DIR to the libclang directory


    python setup.py install
    # there are many other options!

doc.qt.io/qtforpython/gettingstarted.html

Commercial Edition (AD, DC)

How to install

Download packages (.whl files) from account.qt.io
Installing them on a terminal:


            pip install shiboken6-xxxx.whl pyside6-xxxx.whl

(xxxx contains information about architecture, OS and the PySide, Qt, and Python versions)

Commercial Edition (AD Professional)

What is installed?


     ▪️PySide6
      ├── Qt modules              ✅
      ├── pyside6-designer        ✅
      ├── pyside6-rcc             ✅
      ├── pyside6-uic             ✅
      ├── ...tools                ✅
      └── shiboken-wizard         ✅🆕
     ▪️Shiboken6 (module)
      └── shiboken6               ✅
     ▪️Shiboken6_Generator (exe)
      └── shiboken6               ✅

Commercial Edition (AD Enterprise, DC Professional/Enterprise)

What is installed?


     ▪️PySide6
      ├── Qt modules              ✅
      ├── Qt M2M Protocols        ✅🆕
      ├── pyside6-designer        ✅
      ├── pyside6-rcc             ✅
      ├── pyside6-uic             ✅
      ├── ...tools                ✅
      └── shiboken-wizard         ✅🆕
     ▪️Shiboken6 (module)
      └── shiboken6               ✅
     ▪️Shiboken6_Generator (exe)
      └── shiboken6               ✅

Language differences

Python and C++

C++

General purpose and
Multi-paradigm

Python

General purpose and
Multi-paradigm

C++

Statically typed


                int a = 1;
                float b = 4.3;
                string c = "hello";

Python

Dynamically typed


                a = 1
                b = 4.3
                c = "hello"

C++

Compiled


            $ g++ main.cpp -o main
            $ ./main

Python

Interpreted


                $ # no compilation
                $ python main.py

C++

Provides low-level memory manipulation


            QObject *obj = new QObject(...);
            delete obj;

Python

Automatic memory management


            obj = QObject(...)
            del obj # Optional

C++

Code readability


            #include <iostream>

            int main(int argc, char *argv[]) {
                std::cout << "Hello World" << endl;
            }

Python

Code readability
```
            print("Hello World")
```

Qt Example

QMainWindow with a QPushButton

C++


        #ifndef MAINWINDOW_H
        #define MAINWINDOW_H

        #include <QMainWindow>
        #include <QPushButton>

        class MainWindow : public QMainWindow
        {
            Q_OBJECT
            public:
                MainWindow(QWidget *parent = nullptr);
            private slots:
                void handleButton();
            private:
                QPushButton *m_button;
        };

        #endif // MAINWINDOW_H


        #include "mainwindow.h"

        MainWindow::MainWindow(QWidget *parent)
           : QMainWindow(parent)
        {
            m_button = new QPushButton("My Button", this);
            connect(m_button, SIGNAL(clicked()), this, SLOT(handleButton()));
        }

        void MainWindow::handleButton()
        {
            m_button->setText("Ready");
        }


        #include <QApplication>
        #include "mainwindow.h"

        int main(int argc, char *argv[])
        {
            QApplication app(argc, argv);
            MainWindow mainWindow;
            mainWindow.show();
            return app.exec(d);
        }

Python


        import sys
        from pyside6.QtWidgets import QApplication, QMainWindow, QPushButton

        class MainWindow(QMainWindow):
            def __init__(self, parent=None):
                QMainWindow.__init__(self, parent)
                self.button = QPushButton("My Button", self)
                self.button.clicked.connect(self.handleButton)

            def handleButton(self):
                self.button.setText("Ready")

        if __name__ == "__main__":
            app = QApplication(sys.argv)
            mainWindow = MainWindow()
            mainWindow.show()
            sys.exit(app.exec())

Qt Compatibility

Checked on 5.15

(For Qt6, following available modules)

Qt Essentials

Core	D-Bus	GUI	Network
QML	Quick	Quick Controls	Quick Dialogs
Quick Layouts	Quick Test	Test	Widgets

Some modules could be incomplete, please see wiki.qt.io/Qt_for_Python_Missing_Bindings for more information.

Qt Add-Ons

Active Qt	3D	Bluetooth	Concurrent
Help	Image Formats	Multimedia	NFC
OpenGL	PDF	Positioning	Print Support
Quick Widgets	Remote Objects	SCXML	Sensors
Serial Bus	Serial Port	SpatialAudio	SQL
StateMachine	SVG	TextToSpeech	UI Tools
WebChannel	WebEngine	WebSockets	WebView
XML	Charts	Data Visualization	Network Authorization
Quick 3D	Quick Timeline	Shader Tools	Virtual Keyboard
Wayland Compositor	HTTP Server	Quick 3D Physics

Some modules could be incomplete, please see wiki.qt.io/Qt_for_Python_Missing_Bindings for more information.

Value-Add Modules

Qt Automotive Suite

Qt M2M Protocols (1)

Qt for Device Creation

Qt for MCU (2)

(1) KNX is not included, Only MQTT, CoAp, and OpcUA.

(2) Python doesn't have official support on Microcontrollers. Micro/Circuit Python are subsets of Python, and we don't support them.

Platforms

Windows	Linux
macOS	Android (1)
iOS (2)	WebAssembly (3)
Embedded (4)

(1) No official Python support. PoC with third-party tools (in progress)
(2) Python doesn't have official support for iOS
(3) Official support from Python 3.12 (not released). Only research (in progress)
(4) ARM based Linux distributions (ManjaroARM, ArchLinuxARM) provide PySide as a system package. Cross compilation in RaspberryPi OS is possible.

Binding generation

Shiboken

Generation process

Shiboken
死某剣

doc.qt.io/qtforpython/shiboken6

Shiboken

Module

import shiboken6

Helper functions
- isValid(obj)
- getCppPointer(obj)
- isOwnedByPython(obj)
- VoidPtr class

Generator

$ ./shiboken6 ...

Tool to generate bindings
Relies on Library Headers and a Typesystem

Qt Creator

Qt Creator compatibility

Qt Creator templates

Empty application,
Basic Widget application,
Basic Widget application (.ui file), from 4.12,
QtQuick application (QML), from 4.12.

Qt Creator functionality

Can

Create new projects,
Syntax highlight,
Code completion,
Add/remove files,
Generate Python code from ui and qrc files,
Install PySide wheels,
Execute applications,
Select Python interpreter.

Cannot

Install new Python modules,
Remote debugging.

What's there besides the Qt API?

Added value

Qt's a C++ framework, and that might be confusing.

camelCase API is not a Python standard
The usage of setters/getters is not common, in favor of writable properties
Qt has data structures to improve C++'s developers life, but Python too.

The feature option


      # Common Qt structure
      # - Using setter/getter
      # - No writable properties

      table = QTableWidget()
      table.setColumnCount(2)

      button = QPushButton("Add")
      button.setEnabled(False)

      layout = QVBoxLayout()
      layout.addWidget(table)
      layout.addWidget(button)


      from __feature__ import (
        snake_case, true_property
      )

      table = QTableWidget()
      table.column_count = 2

      button = QPushButton("Add")
      button.enabled = False

      layout = QVBoxLayout()
      layout.add_widget(table)
      layout.add_widget(button)

Python compatibility

Usage of Python native structures instead of QVariant
Sequences (Python Lists, Tuples, etc) instead of Qt Sequences
Compatibility with pathlib objects (6.2)
Usage of numpy.array instead of numerical arrays

Shiboken Wizard

Easy graphical way to generate Python bindings from a C++ project.

Shiboken Wizard

Overview video

Common Use Cases

Pure Python Applications

PySide allows Widgets and QML applications
Usually is the preferred option by Python developers
Most examples in doc.qt.io/qtforpython/examples/index.html
Special interaction with other Python modules
- examples/external

Custom Python Bindings (without Qt)

Generating Python bindings
from a C++ library.

Library files:

CMakeLists.txt
icecream.cpp
icecream.h
truck.cpp
truck.h

Shiboken files:

bindings.h (right top)
bindings.xml (right bottom)

★ Check the samplebinding example


        #ifndef BINDINGS_H
        #define BINDINGS_H

        #include "icecream.h"
        #include "truck.h"

        #endif // BINDINGS_H

Custom Python Bindings (with Qt)

Simple typesystem

Python usage

from wiggly import WigglyWidget as WigglyWidgetCPP
from wigglywidget import WigglyWidget as WigglyWidgetPY

# ...
wiggly_widget_py = WigglyWidgetPY(self)
wiggly_widget_cpp = WigglyWidgetCPP(self)
# ...
layout.addWidget(wiggly_widget_py)
layout.addWidget(wiggly_widget_cpp)

★ Check the widgetbinding example

Top: Widget written in Python
Bottom: Widget written in C++ (exposed to Python)

Hybrid Applications (Python and C++)

Embedding Python into a Qt/C++ application

The Text editor interprets Python code to access the Qt/C++ application to modify it.

★ Check the scriptableapplication example

Final remarks

Future steps

Documentation,
Continue improving C++/Python interaction,
Tooling around Shiboken and PySide,
Ready-to-use widgets for other Python modules,
Research on embedded systems.

For more details, refer to our vision blog post
qt.io/blog/2019/08/19/technical-vision-qt-python

Where to start

Product landing page qt.io/qt-for-python
Wiki page pyside.org
Official docs doc.qt.io/qtforpython

Webinars

Creating user interfaces with Qt for Python

youtube.com/watch?v=wKqLaNqxgas

Develop your first Qt for Python application

youtube.com/watch?v=HDBjmSiOBxY

More Videos

doc.qt.io/qtforpython/videos.html

Communication channels

Internal Teams 'Foundations/Qt for Python 🐍'
IRC #qt-pyside on Libera.chat
Mailing list lists.qt-project.org/mailman/listinfo/pyside

More platforms at wiki.qt.io/Qt_for_Python#Community

Qt for Python

General Introduction

Dr. Cristián Maureira-Fredes
R&D Manager @ TQtC

Qt for Python

General Introduction

Naming

The story of PySide

2008

2016

2015

2018

Release information

Python Compatibility

License (1/3)

License (2/3)

License (3/3)

Setup 🔨

Installation (1/3)

Installation (2/3)

Installation (3/3)

Community Edition (OSS)

How to install

Community Edition (OSS)

What is installed?

Community Edition (OSS)

Installing shiboken_generator

Community Edition (OSS)

Installing Shiboken Generator

the simple way

Community Edition (OSS)

Installing Shiboken Generator

the hard way?

Commercial Edition (AD, DC)

How to install

Commercial Edition (AD Professional)

What is installed?

Commercial Edition (AD Enterprise, DC Professional/Enterprise)

What is installed?

Language differences

Python and C++

C++

Python

C++

Python

C++

Python

C++

Python

C++

Python

Qt Example

Qt Compatibility

Qt Essentials

Qt Add-Ons

Value-Add Modules

Platforms

Binding generation

Generation process

Shiboken死某剣

Shiboken

Module

Generator

Qt Creator

Qt Creator compatibility

Qt Creator templates

Qt Creator functionality

What's there besides the Qt API?

Added value

The __feature__ option

Python compatibility

Shiboken Wizard

Shiboken Wizard

Common Use Cases

Pure Python Applications

Custom Python Bindings (without Qt)

Custom Python Bindings (with Qt)

Hybrid Applications (Python and C++)

Final remarks

Future steps

Where to start

Webinars

Communication channels

Qt for Python

Installing `shiboken_generator`

Shiboken
死某剣

The feature option