Difference between revisions of "Qt for Python/GettingStarted"

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[[Category:PySide]]                                                                
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[[Category:Qt for Python]]                                                                                                                              
 +
== Installation ==                                                                                                                                                 
 +
You can install PySide2 via [https://pypi.org/project/PySide2/ PyPi], using [https://download.qt.io/official_releases/QtForPython/ Qt-servers] or by building the source package yourself.                   
 
                                                                                      
 
                                                                                      
== Getting Started ==                                                                                                                                                 
 
You can install PySide2 by building the source package yourself.                   
 
                                                                                   
 
After clonning the official repository you must follow the instructions for         
 
your specific system.                                                                                                                                                   
 
 
=== Platform Requirements ===                                                                                                                                           
 
=== Platform Requirements ===                                                                                                                                           
* '''Python''':                                                                        
+
* '''Python''': Python 3.5+ and Python 2.7 (Please notice there is a known issue with Python 3.6.0, [https://wiki.qt.io/Qt_for_Python/Considerations read more].)
** Python 3 (version >= 3.5 recommended) and Python 2 (version >= 2.7 recommended).
+
* '''Qt''': 5.12 is recommended, but there are Technical Preview wheels for 5.11
* '''Qt''':                                                                            
+
* '''libclang''': The libclang library (C-bindings), recommended: version 6 for PySide2 5.12.
** 5.6 onward are supported, but 5.9 (recommended).
 
* '''CLANG''':                                                                          
 
** The Clang library (C-bindings), version 3.9 or higher is required for building.
 
 
** Prebuilt versions of it can be downloaded from [http://download.qt.io/development_releases/prebuilt/libclang/ download.qt.io].
 
** Prebuilt versions of it can be downloaded from [http://download.qt.io/development_releases/prebuilt/libclang/ download.qt.io].
* '''CMake''':                                                                          
+
* '''CMake (version >= 3.1 required) ''': The build system required by for building PySide2.
** Required by the building system.                                              
+
 
=== Building PySide2 ===                                                                                         
+
=== Install wheel from PyPi ===
 +
Official release wheels of Qt For Python can be installed regularly via pip:
 +
 
 +
    pip install PySide2
 +
 
 +
'''''Note:''' This process will automatically install '''shiboken2''' (python module) as dependency, but the package '''shiboken2_generator''' will not since it's the standalone binary that can generate Python bindings from a Qt/C++ project. We '''highly''' recommend to build PySide2 from scratch if you want to generate your own Python bindings from a Qt/C++ project, because the linking information will not be present in the shiboken2_generator wheel''
 +
 
 +
=== Install wheel from Qt servers ===
 +
 
 +
Official release wheels of Qt for Python can be installed via pip but from Qt servers:
 +
    pip install --index-url=https://download.qt.io/official_releases/QtForPython/ pyside2 --trusted-host download.qt.io
 +
 
 +
Pre-release (snapshot) wheels containing the latest code changes are available at http://download.qt.io/snapshots/ci/pyside/
 +
For example you can install the latest 5.12 snapshot wheel using:
 +
    pip install --index-url=http://download.qt.io/snapshots/ci/pyside/5.12/latest/ pyside2 --trusted-host download.qt.io
 +
 
 +
=== Building PySide2 from scratch ===                                                                                         
 
The building processes are covered in the platform pages.                                                                                                                 
 
The building processes are covered in the platform pages.                                                                                                                 
* [[PySide2_Windows|Windows]]                                                        
+
* [[Qt_for_Python_GettingStarted/Windows|Windows]]
* [[PySide2_X11|Linux/X11]]                                                       
+
* [[Qt_for_Python_GettingStarted/X11|Linux/X11]]                                                       
* [[PySide2_MacOS|macOS]]                                                                                  
+
* [[Qt_for_Python_GettingStarted/MacOS|macOS]]
 +
* Mobile platforms are currently not supported (iOS, Android)
 +
* Embedded Linux platforms are currently not supported (Raspberry Pi, iMX.6)
 +
After cloning the official repository you must follow the instructions for your specific system.                                                                                                                                                   
 +
 
 
==== setup.py build script ====                                                                                                                                           
 
==== setup.py build script ====                                                                                                                                           
 
The script ''setup.py'' in the [http://code.qt.io/cgit/pyside/pyside-setup.git/ top level repository] is used to build and install the PySide2 package. It takes a mode argument (''build'' or ''install'') and several options (more options are documented in setup.py itself).·                                                                                     
 
The script ''setup.py'' in the [http://code.qt.io/cgit/pyside/pyside-setup.git/ top level repository] is used to build and install the PySide2 package. It takes a mode argument (''build'' or ''install'') and several options (more options are documented in setup.py itself).·                                                                                     
 
The main options are:                                                                 
 
The main options are:                                                                 
* ''--qmake=BIN'': Path to ''qmake'' of the Qt library to be used                     
+
* ''--qmake=/path/to/qmake'': Path to ''qmake'' of the Qt library to be used                     
* ''--cmake=BIN'': Path to ''cmake''                                                
+
* ''--cmake=/path/to/cmake'': Path to ''cmake'' binary                                               
* ''--build-tests'': Creates a directory containing the tests along with some helper packages
+
* ''--build-tests'': Builds tests along with some helper packages
* ''--ignore-git'': Prevents ''setup.py'' from cloning and checking out the submodules.·
+
* ''--ignore-git'': Prevents ''setup.py'' from cloning and checking out the git submodules.
* ''--debug'': Build in Debug mode                                                      
+
* ''--debug'': Build in Debug mode (some restrictions apply to Windows, see [[Qt_for_Python_GettingStarted/Windows#Build_considerations|Build considerations]])
* ''--reuse-build'': Rebuilds only modified files (currently does not work for typesystem xml files)
+
* ''--reuse-build'': Rebuilds only modified files
* ''--openssl=BIN'': Path to OpenSSL's binary
+
* ''--openssl=C:\Dev\qtdev\OpenSSL-Win64\bin'': Path to OpenSSL's bindir which contains dlls (Only required for Windows PySide2 packages)
* ''--jobs=#'': Number of # threads to use when building                                                                                                                        
+
* ''--j / parallel #'' : Number of # processes to use when building
 +
* ''--standalone'': Copies over the Qt libraries (and other library dependencies) into the PySide2 package to make it work on other machines (on Windows all builds are standalone, even without specifying the command line argument).
 +
* ''--verbose'': Prints all compiler invocations when building the package.
 +
 
 
A typical invocation looks like:                                                     
 
A typical invocation looks like:                                                     
  python setup.py install --build-tests --jobs=4                                                                                                                       
+
  python setup.py install --build-tests --j 4                                                                                                                       
 
A successful build can be tested by running an example:                               
 
A successful build can be tested by running an example:                               
   python sources/examples/widgets/widgets/tetrix.py                                                                                                   
+
   python examples/widgets/widgets/tetrix.py                                                                                                   
 
You can search for working examples by typing                                         
 
You can search for working examples by typing                                         
 
   cd sources/examples                                                         
 
   cd sources/examples                                                         
 
   git grep "PySide2 port"
 
   git grep "PySide2 port"
  
=== Running Tests ===                                                                 
+
== Running Tests ==                                                                 
 
To perform all the available tests, just execute:                                                                                     
 
To perform all the available tests, just execute:                                                                                     
  python testrunner.py test  > testlog.txt                                                                                                                            
+
  python testrunner.py test  > testlog.txt
 +
 
 +
Note that to successfully run the tests on Windows you need to point the PATH environment variable to the Qt libdir:
 +
set PATH=E:\Qt\5.12\msvc2015_64\bin;%PATH%
 +
 
 
Run only one test(qpainter_test):                                                                                                                                       
 
Run only one test(qpainter_test):                                                                                                                                       
  ctest -R qpainter_test --verbose                                                                                                                                        
+
  ctest -R qpainter_test --verbose
=== Building the Documentation ===                                                  
+
 
                                                                                   
+
== Building the Documentation ==                                                  
This is currently unexplored terrain [https://bugreports.qt.io/browse/PYSIDE-363 PYSIDE-363].
+
 
* The sources are in pyside2/doc                                                   
+
{| style="width:100%; margin-top:10px; background:#fcfcfc; border:1px solid #ccc;"
* libXML2 and libXSLT should be present when building PySide2 (Ubuntu: apt-get install libxml2-dev libxslt1-dev)
+
|
* graphviz + dot should be installed                                               
+
'''Note'''
* QT_SRC_DIR needs to be set                                                       
+
* This is currently possible on Linux and macOS hosts only
* sphinx should be installed (pip install sphinx)                                   
+
* PySide2 needs to be built using make, not ninja.
* qdoc3 is used to generate it                                                                                                                                                                                                           
+
|}
=== Using Qt Creator as a project explorer ===                                       
+
 
 +
Before you build pyside2, ensure that the following requirements are met, to be able to build the documentation:
 +
 
 +
* Install '''libXML2''' and '''libXSLT''' before building PySide2:<code>
 +
apt-get install libxml2-dev libxslt1-dev # Ubuntu
 +
pacman -S libxml2 libxslt # Arch
 +
dnf install libxml2 libxslt # Fedora
 +
 
 +
</code>
 +
* Set <tt>QT_SRC_DIR</tt> with the path to <tt>qtbase</tt>, if you don't want to build documentation based on the Qt sources under <tt><QT_PKG_ROOT>/<QT_VERSION>/Src/qtbase</tt>.<code>
 +
export QT_SRC_DIR=/path/to/qtbase
 +
</code>
 +
* Install '''graphviz''' and '''sphinx''' <code>pip install graphviz sphinx</code>
 +
 
 +
Once your PySide2 is built, navigate to the <tt>*_build/*_release/pyside2</tt> directory and run: <code>
 +
make apidoc
 +
</code>
 +
 
 +
The build first runs <tt>qdoc</tt> on the Qt sources in <tt>$QT_SRC_DIR</tt> to generate the webxml files, which are then parsed by shiboken to generate ''reStructuredText'' files. In the final step, sphinx is run on the rst files to generate HTMLs.
 +
 
 +
You could also use the ''docrsts'' make target to generate only the reStructuredText files.
 +
 
 +
== Using Qt Creator as a project explorer ==                                       
 
Qt Creator 4.0+ can be used to open the PySide and Shiboken CMakeLists.txt files as projects, and thus provide usual IDE features for developing PySide - project file navigation, code completion (C++ only), following symbols under cursor (C++ only), syntax highlighting, locator usage, debugging, etc.
 
Qt Creator 4.0+ can be used to open the PySide and Shiboken CMakeLists.txt files as projects, and thus provide usual IDE features for developing PySide - project file navigation, code completion (C++ only), following symbols under cursor (C++ only), syntax highlighting, locator usage, debugging, etc.
 
                                                                                      
 
                                                                                      
Line 60: Line 103:
 
                                                                                      
 
                                                                                      
 
The steps for opening the projects in Qt Creator are:                                 
 
The steps for opening the projects in Qt Creator are:                                 
# Open pyside-setup/sources/shiboken2/CMakeLists.txt, and specify a 5.6 Qt Kit to be used
+
# Open pyside-setup/sources/shiboken2/CMakeLists.txt, and specify a 5.12 Qt Kit to be used
 
# Build the project as usual (by pressing the build icon for instance)               
 
# Build the project as usual (by pressing the build icon for instance)               
# Open pyside-setup/sources/pyside2/CMakeLists.txt, and specify the same 5.6 Qt Kit   
+
# Open pyside-setup/sources/pyside2/CMakeLists.txt, and specify the same 5.12 Qt Kit   
 
# Go to projects tab, and under the Build / CMake section find the Shiboken2_DIR setting. You have to specify the path to the folder where the Shiboken CMake package was installed when you compiled Shiboken from the terminal·
 
# Go to projects tab, and under the Build / CMake section find the Shiboken2_DIR setting. You have to specify the path to the folder where the Shiboken CMake package was installed when you compiled Shiboken from the terminal·
# An example path under MacOS is /Users/user/Dev/pyside2-setup/pyside_install/py2.7-qt5.6.1-64bit-debug/lib/cmake/Shiboken2-2.0.0. The path has to be adjusted depending on the user folder name, the version of python and qt, etc
+
# An example path under MacOS is /Users/user/Dev/pyside2-setup/pyside_install/py3.6-qt5.12.1-64bit-debug/lib/cmake/Shiboken2-2.0.0. The path has to be adjusted depending on the user folder name, the version of python and qt, etc
# (Optional) On MacOS you also have to set the ALTERNATIVE_QT_INCLUDE_DIR setting to the Qt kit include path (e.g. /Users/user/Dev/qt56_source/include)                                                                                                                                                                                                                                                                                                                                     
+
# (Optional) On MacOS you also have to set the ALTERNATIVE_QT_INCLUDE_DIR setting to the Qt kit include path (e.g. /Users/user/Dev/qt511_source/include)                                                                                                                                                                                                                                                                                                                                     
 
# Apply the CMake configuration changes (by pressing the button), and you should be able to build PySide
 
# Apply the CMake configuration changes (by pressing the button), and you should be able to build PySide
 
                                                                                      
 
                                                                                      
 
Now you can use the project explorer to look through the source cpp files, python files, use the locator feature to open files and file classes / methods, and other features that Qt Creator provides.
 
Now you can use the project explorer to look through the source cpp files, python files, use the locator feature to open files and file classes / methods, and other features that Qt Creator provides.
 +
 +
== Troubleshooting / Known Issues ==
 
                                                                                      
 
                                                                                      
== Troubleshooting ==                                                             
+
* Qt 5.9 does not work with OpenSSL 1.1                                         
                                                                                   
+
** When doing a custom Qt build (some unspecified versions for now), It is necessary to have an OpenSSL version of 1.0.x, since there are compatibility issues with newer versions of OpenSSL ([https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes#Qt see details])
* PySide2 5.9 does not work with OpenSSL 1.1                                         
 
**It is necessary to have OpenSSL 1.0.x to work around Qt and PySide v5.9, since there are compatibility issues with newer versions of OpenSSL ([https://wiki.openssl.org/index.php/OpenSSL_1.1.0_Changes#Qt see details])
 
 
* PySide2 looks at the system installation if the local Qt version does not have a required module
 
* PySide2 looks at the system installation if the local Qt version does not have a required module
 
**The only workaround is to uninstall any module from the system, then PySide2 can look at only the Qt path currently being use.
 
**The only workaround is to uninstall any module from the system, then PySide2 can look at only the Qt path currently being use.
* Missing libraries when trying examples
+
* Qt packages that directly link to OpenSSL (as opposed to runtime discovery) are not currently supported.
** When doing local builds of Qt on Linux, the environment LD_LIBRARY_PATH needs to be set to point to the location of the Qt library when running examples, as otherwise they are not found by Python. On macOS you will need to set either the DYLD_LIBRARY_PATH or DYLD_FRAMEWORK_PATH environment variables.
+
* Make sure that the Python environment location where the PySide2 package will be installed is writable (otherwise you might get various permission denied errors). The install location can be found with 99% probability by running:
 +
python -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())"
 +
* Building failing because graphviz wasn't found. If you're using pyenv and installed it using pip, try to install it using your package manager:<syntaxhighlight>
 +
dnf install graphviz.x86_64 #Fedora
 +
</syntaxhighlight>

Latest revision as of 08:52, 9 September 2019

Installation

You can install PySide2 via PyPi, using Qt-servers or by building the source package yourself.

Platform Requirements

  • Python: Python 3.5+ and Python 2.7 (Please notice there is a known issue with Python 3.6.0, read more.)
  • Qt: 5.12 is recommended, but there are Technical Preview wheels for 5.11
  • libclang: The libclang library (C-bindings), recommended: version 6 for PySide2 5.12.
  • CMake (version >= 3.1 required) : The build system required by for building PySide2.

Install wheel from PyPi

Official release wheels of Qt For Python can be installed regularly via pip:

   pip install PySide2

Note: This process will automatically install shiboken2 (python module) as dependency, but the package shiboken2_generator will not since it's the standalone binary that can generate Python bindings from a Qt/C++ project. We highly recommend to build PySide2 from scratch if you want to generate your own Python bindings from a Qt/C++ project, because the linking information will not be present in the shiboken2_generator wheel

Install wheel from Qt servers

Official release wheels of Qt for Python can be installed via pip but from Qt servers:

   pip install --index-url=https://download.qt.io/official_releases/QtForPython/ pyside2 --trusted-host download.qt.io

Pre-release (snapshot) wheels containing the latest code changes are available at http://download.qt.io/snapshots/ci/pyside/ For example you can install the latest 5.12 snapshot wheel using:

   pip install --index-url=http://download.qt.io/snapshots/ci/pyside/5.12/latest/ pyside2 --trusted-host download.qt.io

Building PySide2 from scratch

The building processes are covered in the platform pages.

  • Windows
  • Linux/X11
  • macOS
  • Mobile platforms are currently not supported (iOS, Android)
  • Embedded Linux platforms are currently not supported (Raspberry Pi, iMX.6)

After cloning the official repository you must follow the instructions for your specific system.

setup.py build script

The script setup.py in the top level repository is used to build and install the PySide2 package. It takes a mode argument (build or install) and several options (more options are documented in setup.py itself).· The main options are:

  • --qmake=/path/to/qmake: Path to qmake of the Qt library to be used
  • --cmake=/path/to/cmake: Path to cmake binary
  • --build-tests: Builds tests along with some helper packages
  • --ignore-git: Prevents setup.py from cloning and checking out the git submodules.
  • --debug: Build in Debug mode (some restrictions apply to Windows, see Build considerations)
  • --reuse-build: Rebuilds only modified files
  • --openssl=C:\Dev\qtdev\OpenSSL-Win64\bin: Path to OpenSSL's bindir which contains dlls (Only required for Windows PySide2 packages)
  • --j / parallel # : Number of # processes to use when building
  • --standalone: Copies over the Qt libraries (and other library dependencies) into the PySide2 package to make it work on other machines (on Windows all builds are standalone, even without specifying the command line argument).
  • --verbose: Prints all compiler invocations when building the package.

A typical invocation looks like:

python setup.py install --build-tests --j 4                                                                                                                       

A successful build can be tested by running an example:

 python examples/widgets/widgets/tetrix.py                                                                                                  

You can search for working examples by typing

 cd sources/examples                                                        
 git grep "PySide2 port"

Running Tests

To perform all the available tests, just execute:

python testrunner.py test  > testlog.txt

Note that to successfully run the tests on Windows you need to point the PATH environment variable to the Qt libdir:

set PATH=E:\Qt\5.12\msvc2015_64\bin;%PATH%

Run only one test(qpainter_test):

ctest -R qpainter_test --verbose

Building the Documentation

Note

  • This is currently possible on Linux and macOS hosts only
  • PySide2 needs to be built using make, not ninja.

Before you build pyside2, ensure that the following requirements are met, to be able to build the documentation:

  • Install libXML2 and libXSLT before building PySide2:
    apt-get install libxml2-dev libxslt1-dev # Ubuntu
    pacman -S libxml2 libxslt # Arch
    dnf install libxml2 libxslt # Fedora
    
  • Set QT_SRC_DIR with the path to qtbase, if you don't want to build documentation based on the Qt sources under <QT_PKG_ROOT>/<QT_VERSION>/Src/qtbase.
    export QT_SRC_DIR=/path/to/qtbase
    
  • Install graphviz and sphinx
    pip install graphviz sphinx
    
Once your PySide2 is built, navigate to the *_build/*_release/pyside2 directory and run:
make apidoc

The build first runs qdoc on the Qt sources in $QT_SRC_DIR to generate the webxml files, which are then parsed by shiboken to generate reStructuredText files. In the final step, sphinx is run on the rst files to generate HTMLs.

You could also use the docrsts make target to generate only the reStructuredText files.

Using Qt Creator as a project explorer

Qt Creator 4.0+ can be used to open the PySide and Shiboken CMakeLists.txt files as projects, and thus provide usual IDE features for developing PySide - project file navigation, code completion (C++ only), following symbols under cursor (C++ only), syntax highlighting, locator usage, debugging, etc.

Currently there is a limitation that Shiboken has to be built first using the terminal, because the installed shiboken CMake packages will have to be specified for the PySide project in Qt Creator.

The steps for opening the projects in Qt Creator are:

  1. Open pyside-setup/sources/shiboken2/CMakeLists.txt, and specify a 5.12 Qt Kit to be used
  2. Build the project as usual (by pressing the build icon for instance)
  3. Open pyside-setup/sources/pyside2/CMakeLists.txt, and specify the same 5.12 Qt Kit
  4. Go to projects tab, and under the Build / CMake section find the Shiboken2_DIR setting. You have to specify the path to the folder where the Shiboken CMake package was installed when you compiled Shiboken from the terminal·
  5. An example path under MacOS is /Users/user/Dev/pyside2-setup/pyside_install/py3.6-qt5.12.1-64bit-debug/lib/cmake/Shiboken2-2.0.0. The path has to be adjusted depending on the user folder name, the version of python and qt, etc
  6. (Optional) On MacOS you also have to set the ALTERNATIVE_QT_INCLUDE_DIR setting to the Qt kit include path (e.g. /Users/user/Dev/qt511_source/include)
  7. Apply the CMake configuration changes (by pressing the button), and you should be able to build PySide

Now you can use the project explorer to look through the source cpp files, python files, use the locator feature to open files and file classes / methods, and other features that Qt Creator provides.

Troubleshooting / Known Issues

  • Qt 5.9 does not work with OpenSSL 1.1
    • When doing a custom Qt build (some unspecified versions for now), It is necessary to have an OpenSSL version of 1.0.x, since there are compatibility issues with newer versions of OpenSSL (see details)
  • PySide2 looks at the system installation if the local Qt version does not have a required module
    • The only workaround is to uninstall any module from the system, then PySide2 can look at only the Qt path currently being use.
  • Qt packages that directly link to OpenSSL (as opposed to runtime discovery) are not currently supported.
  • Make sure that the Python environment location where the PySide2 package will be installed is writable (otherwise you might get various permission denied errors). The install location can be found with 99% probability by running:
python -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())"
  • Building failing because graphviz wasn't found. If you're using pyenv and installed it using pip, try to install it using your package manager:
    dnf install graphviz.x86_64 #Fedora