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{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"Pyside support and usage","articleBody":"@sloretz \r\n### Motivation\r\nI was working on https://github.com/ros2/rviz/pull/889 and I have found a couple of issues with qt python integration, especially dependencies. I was looking into creating python bindings for rviz only with PySide2. No I was wondering how to resolve dependencies and turns out there is no key for pyside2 is not in rosdistro but partially in python_qt5_bindings. This all seems kind of unorganised and super hard if you want to create bindings that only support one of the to binding generators. \r\n\r\n### Problems\r\n**pyside2 in rosdistro:**\r\nThe most essential packages python3-pyside2.qtcore, python3-pyside2.qtgui and python3-pyside2.qtwidgets are not installed by libpyside2-dev, libshiboken2-dev or shiboken in rosdistro. python-pyside2 does not even exist in Ubuntu.\r\n\r\n```\r\npython-qt5-bindings:\r\n  arch: [python2-pyqt5]\r\n  debian:\r\n    buster: [pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-sip-dev, qtbase5-dev]\r\n    jessie: [pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-sip-dev, qtbase5-dev]\r\n    stretch: [pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-sip-dev, qtbase5-dev]\r\n  fedora: [python-qt5-devel, sip]\r\n  freebsd: [py27-qt5]\r\n  gentoo: ['dev-python/PyQt5[gui,widgets]']\r\n  nixos: [pythonPackages.pyqt5]\r\n  openembedded: ['${PYTHON_PN}-pyqt5@meta-qt5']\r\n  opensuse: [python2-qt5-devel, python2-sip-devel]\r\n  slackware: [PyQt5]\r\n  ubuntu:\r\n    artful: [pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-sip-dev]\r\n    bionic: [pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-sip-dev]\r\n    wily: [libpyside2-dev, libshiboken2-dev, pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-pyside2, python-sip-dev, shiboken2]\r\n    xenial: [libpyside2-dev, libshiboken2-dev, pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-pyside2, python-sip-dev, shiboken2]\r\n    yakkety: [libpyside2-dev, libshiboken2-dev, pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-pyside2, python-sip-dev, shiboken2]\r\n    zesty: [pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python-sip-dev]\r\n```\r\n\r\nBy changing to the following we would at least install the same libraries for pyqt and pyside on Ubuntu:\r\n```\r\n[libpyside2-dev, libshiboken2-dev, pyqt5-dev, python-pyqt5, python-pyqt5.qtsvg, python3-pyside.qtcore, python3-pyside.qtdbus, python3-pyside.qtdesigner, python3-pyside.qtgui, python3-pyside.qthelp, python3-pyside.qtnetwork, python3-pyside.qtprintsupport, python3-pyside.qttest, python3-pyside.qtwidgets, python3-pyside.qtxml, python3-pyside.qtsvg, python-sip-dev, shiboken2]\r\n```\r\n\r\n**Interoperability of PyQt and PySide**:\r\nAdditionally, why are we not using QtPy(https://github.com/spyder-ide/qtpy) (MIT LICENSE), which has much better support for interoperability between pyside and pyqt, than just replacing names, especially for edge cases. There are also ubuntu/debian binaries in universe.\r\n\r\n### Conclusion\r\nQt for Python support is super shady and not well organised. It is very hard to understand which systemdeps to reference to install what. In addition python_qt_bindings will install both pyside2 and pyqt5. Generally, I would rather like to see an approach similar to the rmw's where we have a default and the option to install and use the the other. \r\n\r\n### Suggestion\r\n* Add python-qtpy to rosdep\r\n* Update python_qt_bindings to use QtPy and depreceate importing via python_qt_bindings\r\n* Use python_qt_bindings package to distribute the CMAKE files for binding generation\r\n* Update python-qt5-bindings rosdep key to install only default bindings (Use pyqt5 as default, as this seems to be defacto what is happening right now)\r\n* Create python-pyqt5 rosdep key\r\n* Create python-pyside2 rosdep key\r\n* Create additional rosdep keys for both pyside and pyqt in rosdistro for each extra qt lib (e.g. python-pyqt5.qtsvg and python-pyside2.qtsvg)\r\n\r\n\r\n\r\n\r\n\r\n\r\n","author":{"url":"https://github.com/hellantos","@type":"Person","name":"hellantos"},"datePublished":"2022-08-29T08:10:05.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":6},"url":"https://github.com/114/python_qt_binding/issues/114"}