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[[Category:PySide]]
[[Category:Qt for Python]]                                                                                                                              
== Considerations before starting ==
==Official documentation==


PySide2 supports Python 2 (recommended: 2.7 onwards, Compatibility module ''six'' installed) and Python 3 (recommended: 3.5 onwards).  
Refer to the [https://doc.qt.io/qtforpython/gettingstarted.html official docs] to start building and using Qt for Python.


On Windows, it is recommended to use Python 3 and build with MSVC2015. Python 2 requires building with MSVC2008. The Qt library has to be built with the same version of MSVC as Python and PySide2.
==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.


Currently, Qt 5.6 and Qt 5.9 onwards are supported. Note that the branch of the [https://code.qt.io/cgit/pyside/pyside-setup.git pyside-setup] repository must match that of the Qt version used.
The steps for opening the projects in Qt Creator are:                              
PySide versions following 5.6 (so 5.9 and dev) use a C++ parser based on [http://clang.org/ Clang]).


The Clang library (C-bindings), version 3.9 or
#Open '''pyside-setup/sources/shiboken2/CMakeLists.txt''' and specify a 5.12+ Qt Kit to be used
higher is required for building. Prebuilt versions of it can be downloaded from
#Build the project as usual (by pressing the '''build''' icon for instance)
[http://download.qt.io/development_releases/prebuilt/libclang/ download.qt.io].
#Open '''pyside-setup/sources/pyside2/CMakeLists.txt''' and specify the same 5.12+ Qt Kit
 
#Go to the 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·
Qt needs to be built with the ''QtXmlPatterns'' module.
#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/qt511_source/include''')
== Development ==
#Apply the CMake configuration changes (by pressing the button), and you should be able to build PySide
 
                                                                                   
Development happens in the 5.9 and dev branches of the [http://code.qt.io/cgit/pyside/pyside-setup.git/ pyside-setup repository].
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.
 
Build instructions can be found in the sections [[#Building PySide2|below]].
 
The top level repository has the following submodules:
* sources/pyside2-examples: [http://code.qt.io/cgit/pyside/examples.git/ Examples]
* sources/pyside2-tools: uic, rcc tools
* wiki: Wiki
 
Contributions follow the [[Qt_Project_Guidelines|standard process]].
 
Building requires [https://cmake.org/ CMake].
 
It is helpful to have debug binaries and/or symbols for Python available. On Windows, this is done by choosing ''Customized Installation'' when installing Python and ticking the respective check boxes. On Linux, debug packages can be installed separately. For Ubuntu, the packages python3-dbg, libpython3-dbg provide a debug binary python3-dbg. On macOS you will need to build the Python interpreter with debug symbols by hand.
 
It is also recommended to use a [http://docs.python-guide.org/en/latest/dev/virtualenvs/ Virtual Environment] for testing to be able to always start from a clean base and avoid issues with write permissions in installations.
 
On Linux, the command
virtualenv -p /usr/bin/python3-dbg testenv
creates a Virtual Environment named ''testenv'' for debugging purposes. On Windows, an installation step may be required:
python -m pip install virtualenv
python -m virtualenv testenv
 
The Virtual Environment is activated by
  source testenv/bin/activate
or
CALL testenv\Scripts\activate.bat
 
Before building the first time, the module [http://www.sphinx-doc.org/en/1.4.9/ Sphinx] should be installed into the virtual environment:
pip install sphinx
 
=== Building PySide2 ===
 
General build instructions can be found in the [http://code.qt.io/cgit/pyside/pyside-setup.git/tree/README.md?h=5.9 README.md] file.
 
Sample / specific instructions for building on Ubuntu can be found [[#How to build from sources|below]].
 
==== Requirements ====
* Windows, Linux or macOS (Android / iOS / embedded is not supported at the moment)
* Qt package from https://www.qt.io or a custom build of Qt (preferably '''Qt 5.9''' or '''Qt 5.6''')
* Python from https://www.python.org/downloads/ ('''Python 3.6''' or '''Python 2.7''')
* '''GCC''' (Linux), '''Xcode''' (macOS), '''MSVC2015''' (for Python 3 on Windows), MSCVC2008 (for Python 2 on Windows)
* CMake from https://cmake.org/download/ ('''>= 3.1''')
* libclang (required for the 5.9 and dev branches) from [http://download.qt.io/development_releases/prebuilt/libclang/ download.qt.io] ('''>= 3.9''')
* [https://llvm.org/ LLVM]
* virtualenv (optional but recommended)
* Python sphinx package for documentation (optional, pip install sphinx)
 
==== 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 main options are:
* --qmake=<binary> Path to ''qmake'' of the Qt library to be used
* --cmake=<binary> Path to ''cmake''
* --build-tests: Creates a directory containing the tests along with some helper packages
* --ignore-git: Prevents ''setup.py'' from cloning and checking out the submodules.
* --debug: Build in Debug mode
* --reuse-build: Rebuilds only modified files (currently does not work for typesystem xml files)
* --openssl: Path to OpenSSL
* --jobs : Number of threads to use when building
 
If you are on Linux, before you call ''setup.py'' you must configure your system to use Clang as C and C++ compiler:
 
export CC=/usr/bin/clang
export CXX=/usr/bin/clang++
 
A typical invocation looks like:
setup.py install --build-tests --jobs=4
 
A successful build can be tested by running an example:
  python sources/pyside2-examples/examples/widgets/widgets/tetrix.py
 
You can search for working examples by typing
  cd sources/pyside2-examples
  git grep "PySide2 port"
 
Note: 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.
 
=== Running Tests ===
 
python testrunner.py test  > testlog.txt
 
Run only one test(qpainter_test):
 
ctest -R qpainter_test --verbose
 
=== Building the Documentation ===
 
This is currently unexplored terrain [https://bugreports.qt.io/browse/PYSIDE-363 PYSIDE-363].
* The sources are in pyside2/doc
* libXML2 and libXSLT should be present when building PySide2 (Ubuntu: apt-get install libxml2-dev libxslt1-dev)
* graphviz + dot should be installed
* QT_SRC_DIR needs to be set
* sphinx should be installed (pip install sphinx)
* qdoc3 is used to generate it
 
=== <span id="How to build from sources"></span>How to build from sources against Qt 5.7, Qt 5.8, Qt 5.9 on Ubuntu 16.04 LTS 64bit ([http://www.acronymfinder.com/Works-on-My-Machine-(WOMM).html WOMM]) ===
 
==== prerequisites ====
Qt 5.7+ (better from http://download.qt.io/official_releases/online_installers/qt-unified-linux-x64-online.run)
libclang-release_39-linux-Rhel7.2-gcc5.3-x86_64.7z from http://download.qt.io/development_releases/prebuilt/libclang/
 
==== step 01 - libclang ====
wget http://download.qt.io/development_releases/prebuilt/libclang/libclang-release_39-linux-Rhel7.2-gcc5.3-x86_64.7z
7z x libclang-release_39-linux-Rhel7.2-gcc5.3-x86_64.7z
 
export CLANG_INSTALL_DIR=$PWD/libclang
 
==== step 02 - getting pyside2 ====
git clone --recursive https://codereview.qt-project.org/pyside/pyside-setup
cd pyside-setup && git checkout 5.9
 
''(commit 8fee86dd7b58c13db39c7c354558119a6346fa5a builds fine)''
 
==== step 03 - building pyside2 ====
python setup.py build --qmake=/home/filippo/Qt/5.7/gcc_64/bin/qmake  --openssl=/usr/bin/openssl --build-tests --ignore-git --jobs=4
''(change the path accordingly on your system!)''
 
==== step 04 - install pyside2 in your env ====
ln -s /home/filippo/tmp/pyside2/src/pyside-setup/pyside_package/PySide2 /home/filippo/tmp/pyside2/lib/python2.7/site-packages/PySide2
ln -s /home/filippo/tmp/pyside2/src/pyside-setup/pyside_package/PySide2.egg-info/ /home/filippo/tmp/pyside2/lib/python2.7/site-packages/PySide2.egg-info
''(change the paths accordingly on your system!)''
 
==== step 05 - play tetrix ====
LD_LIBRARY_PATH=/home/filippo/Qt/5.7/gcc_64/lib/ python sources/pyside2-examples/examples/widgets/widgets/tetrix.py
''(change the paths accordingly on your system!)''
 
=== Building PySide2 from Source Packages Provided by Distributions ===
 
PySide2 is ideally built from a source-based package provided for your platform's package manager (e.g., Arch Linux's [https://wiki.archlinux.org/index.php/pacman pacman], Gentoo Linux's [https://wiki.gentoo.org/wiki/Portage Portage]). If your platform fails to provide such a package, PySide2 may also be manually built from scratch as a fallback.
 
==== Arch Linux ====
 
Arch Linux automates PySide2 installation from source via the [https://aur.archlinux.org AUR] package [https://aur.archlinux.org/packages/python-pyside2-git/ ''python-pyside2-git''] as follows:
 
===== Using git =====
 
1. Download ''python-pyside2-git''.
 
git clone https://aur.archlinux.org/python-pyside2-git.git
 
2. Install ''python-pyside2-git''.
 
cd python-pyside2-git
makepkg -srci
 
(An installation using Python 2.7 is also possible through the [https://aur.archlinux.org AUR] package [https://aur.archlinux.org/packages/python2-pyside2-git/ ''python2-pyside2-git''] package)
 
===== Using [https://archlinux.fr/yaourt-en ''Yaourt''] =====
 
yaourt -S python-pyside2-git
 
==== Gentoo Linux ====
 
Gentoo Linux automates PySide2 installation from source via the [https://github.com/leycec/raiagent/tree/master/dev-python/pyside ''pyside-9999:2''] package hosted by the [https://github.com/gentoo/qt official qt overlay] as follows:
 
* Install [https://wiki.gentoo.org/wiki/Layman layman] (if you haven't already).
 
emerge layman
echo 'source /var/lib/layman/make.conf' >> /etc/portage/make.conf
 
* Add the [https://github.com/gentoo/qt qt overlay].
 
layman -a qt
 
* Synchronize overlays.
 
layman -S
 
* Unmask ''pyside-9999:2'' and ''shiboken-9999:2''.


echo '~dev-python/pyside-9999:2 **\n~dev-python/shiboken-9999:2 **' >> /etc/portage/package.accept_keywords
==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 ([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
**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:


* '''(Optional)''' Enable ''pyside-9999:2'' USE flags. Most USE flags currently supported by the official [https://packages.gentoo.org/packages/dev-python/PyQt5 PyQt5 ebuild] are also supported by the ''pyside-9999:2'' ebuild. For example:
  python -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())"
 
  echo '~dev-python/pyside-9999:2 concurrent designer help testlib widgets -kde -phonon -script -sql -webkit -webchannel -webengine' >> /etc/portage/package.use
 
* Install ''pyside-9999:2'' and ''shiboken-9999:2''.
 
emerge pyside-9999:2
 
==== Manually on Ubuntu (Debug Build) ====
 
This is useful for debugging into the interpreter as well as into extensions.
Roughly the steps are the following:
 
git clone https://github.com/python/cpython python3.6 && cd python3.6 && git checkout 3.6
sudo apt-get build-dep python3.5 # (at time of writing 3.6 was not packaged yet, but it doesn't matter, it's just build dependencies)
mkdir build_debug && cd build_debug
../configure --with-pydebug --enable-shared --prefix=/home/CHANGE_ME/python36_installed LDFLAGS="-Wl,--rpath=/home/CHANGE_ME/python36_installed/lib" # (you can modify the install path to any directory you wish, make sure to change it in the rpath setting as well)
make -j4 && make install
virtualenv -p /home/CHANGE_ME/python36_installed/bin/python3.6dm py36
 
After that you can build PySide2 using the custom Python interpreter, using the virtualenv you created in the last step. Make sure to change the paths to reflect your own directory structure.
cd /path/to/location/of/pyside/supermodule
python setup.py install --qmake=/home/CHANGE_ME/qt56/bin/qmake --cmake=/usr/bin/cmake --openssl=/usr/bin/openssl --debug --jobs=4 --ignore-git --build-tests
 
=== 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:
# Open pyside-setup/sources/shiboken2/CMakeLists.txt, and specify a 5.6 Qt Kit to be used
# 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
# 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
# (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)
# 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 ===


* PySide2 5.9 does not work with OpenSSL 1.1
*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>
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])
dnf install graphviz.x86_64 #Fedora
* PySide2 looks at the system installation if the local Qt version does not have a required module
</syntaxhighlight>
The only workaround is to uninstall any module from the system, then PySide2 can look at only the Qt path currently being use.
*20220727 Urgent update: If you build PySide with a custom built Python, you should build python with the following options: <syntaxhighlight lang="shell">
PYTHON_CONFIGURE_OPTS="--enable-shared --with-trace-refs"
</syntaxhighlight>For example:<syntaxhighlight lang="shell">
PYTHON_CONFIGURE_OPTS="--enable-shared --with-trace-refs" pyenv install -kg 3.9.13
</syntaxhighlight>This makes PySide2 work without the limited API. <br />

Latest revision as of 14:08, 27 July 2022

Official documentation

Refer to the official docs to start building and using Qt for Python.

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 the 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
  • 20220727 Urgent update: If you build PySide with a custom built Python, you should build python with the following options: 
    PYTHON_CONFIGURE_OPTS="--enable-shared --with-trace-refs"
    For example:
    PYTHON_CONFIGURE_OPTS="--enable-shared --with-trace-refs" pyenv install -kg 3.9.13
    This makes PySide2 work without the limited API.
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