Bundling Qt Using pyqt-bundle
PyQt wheels can contain a bundled copy of the relevent parts of Qt. The main reason for doing this is so that users can install a complete PyQt environment with a single pip install.
A bundled copy may also be replaced by a newer release of Qt. Given the ABI guarantees made by Qt (i.e. that a later version of Qt should be able to replace an earlier version without having to re-compile an application) then it should be perfectly possible to bundle a later version of Qt that has a later minor version number with a version of PyQt that has an earlier minor version number. For example it should be possible to bundle Qt v5.15.2 with PyQt v5.12.0.
The other use case is when you want to bundle a development version of Qt with a version of PyQt so that the development version can be tested in a Python environment.
The ABI guarantees made by Qt do not apply to the
QAxContainer module. This is only guaranteed to work if
the version of Qt being bundled is exactly the same as the version of Qt
that PyQt was built against.
The pyqt-bundle program is provided as a means of bundling the relevant parts of a local Qt installation with a wheel, replacing any existing copy. You can also use it to produce a stripped down version of PyQt that contains only those modules you actually want to use.
pyqt-bundle assumes that the Qt installation has been created from one of the LGPL or commercial binary installers provided by The Qt Company. It may also work with a Qt installation built from source but this is unsupported.
On Windows the binary installer for the latest supported version of MSVC must be used. Also on Windows pyqt-bundle also handles the MSVC runtime DLLs and the OpenSSL DLLs.
pyqt-bundle will not update the platform tag of a wheel. Some platform tags can embed additional requirements (e.g. the minimum required version of macOS is embedded in the platform tag of a macOS wheel). If you bundle a later version of Qt with a more restrictive requirement then you should rename the wheel to reflect this.
The syntax of the pyqt-bundle command line is:
pyqt-bundle [options] wheel
The full set of command line options is:
- -h, --help
Display a help message and exit.
- -V, --version
Display the version number and exit.
- --build-tag-suffix SUFFIX
SUFFIXis appended to the build tag in the name of the updated wheel. The build tag is the version number of the copy of Qt being bundled.
- --arch ARCH
On macOS, when bundling Qt v6.2 or later, support for the
arm64) only is included.
- --exclude NAME
NAMEbindings are excluded from the wheel. This option may be specified multiple times.
If a file cannot be found in the Qt installation being bundled then it is ignored instead of being teated as an error. This allows unsupported or non-standard Qt installation to be bundled but may result in a wheel that does not work.
On Windows the
vcruntime140.dllMSVC runtime DLLs will not be included in the wheel.
On Windows the OpenSSL DLLs (included with pyqt-bundle) will not be included in the wheel.
- --openssl-dir DIR
On Windows the OpenSSL DLLs included in the wheels are taken from
DIRinstead of the DLLs included with pyqt-bundle. (Qt v5.12.4 and later are configured for OpenSSL v1.1.1. Earlier versions of Qt are configured for OpenSSL v1.0.2.)
- --qt-dir DIR
DIRcontains the LGPL or commercial Qt installation to be bundled. The directory is what Qt refers to as the prefix directory, i.e. the architecture specific directory containing the
libetc. directories. This option must be specified.
By convention a wheel without a copy of Qt bundled does not have a build tag. A wheel with a copy of Qt bundled has a build tag corresponding to the version of Qt.
Bundling Qt6 Additional Libraries
Starting with Qt v6.1.0 the online installer now includes binaries for the additional libraries, therefore the steps described below are no longer necessary.
Unlike Qt5, the Qt6 online installer only provides binaries for the core Qt libraries. It provides the sources for the additional libraries (e.g. Qt 3D) and these must be built and installed before they can be bundled. While the Qt documentation talks about using the conan package manager to do this it isn’t actually necessary.
To build and additional library make sure you have CMake and
ninja installed and on
PATH. Change to the library’s
Src subdirectory and run:
cmake -G Ninja -DCMAKE_INSTALL_PREFIX=/path/to/qt-prefix-directory
The Qt prefix directory is the name of the architecture-specific directory of a
Qt installation. It is
gcc_64 on Linux,
clang_64 on macos and
msvc2019_64 on Windows.