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Diffstat (limited to 'python/README.rst')
| -rw-r--r-- | python/README.rst | 47 |
1 files changed, 38 insertions, 9 deletions
diff --git a/python/README.rst b/python/README.rst index dcf993819d..9c1fceaee7 100644 --- a/python/README.rst +++ b/python/README.rst @@ -7,8 +7,7 @@ then by package (e.g. ``qemu/machine``, ``qemu/qmp``, etc). ``setup.py`` is used by ``pip`` to install this tooling to the current environment. ``setup.cfg`` provides the packaging configuration used by -``setup.py`` in a setuptools specific format. You will generally invoke -it by doing one of the following: +``setup.py``. You will generally invoke it by doing one of the following: 1. ``pip3 install .`` will install these packages to your current environment. If you are inside a virtual environment, they will @@ -17,12 +16,13 @@ it by doing one of the following: 2. ``pip3 install --user .`` will install these packages to your user's local python packages. If you are inside of a virtual environment, - this will fail; you likely want the first invocation above. + this will fail; you want the first invocation above. -If you append the ``-e`` argument, pip will install in "editable" mode; -which installs a version of the package that installs a forwarder -pointing to these files, such that the package always reflects the -latest version in your git tree. +If you append the ``--editable`` or ``-e`` argument to either invocation +above, pip will install in "editable" mode. This installs the package as +a forwarder ("qemu.egg-link") that points to the source tree. In so +doing, the installed package always reflects the latest version in your +source tree. Installing ".[devel]" instead of "." will additionally pull in required packages for testing this package. They are not runtime requirements, @@ -30,16 +30,45 @@ and are not needed to simply use these libraries. Running ``make develop`` will pull in all testing dependencies and install QEMU in editable mode to the current environment. +(It is a shortcut for ``pip3 install -e .[devel]``.) See `Installing packages using pip and virtual environments <https://packaging.python.org/guides/installing-using-pip-and-virtual-environments/>`_ for more information. +Using these packages without installing them +-------------------------------------------- + +These packages may be used without installing them first, by using one +of two tricks: + +1. Set your PYTHONPATH environment variable to include this source + directory, e.g. ``~/src/qemu/python``. See + https://docs.python.org/3/using/cmdline.html#envvar-PYTHONPATH + +2. Inside a Python script, use ``sys.path`` to forcibly include a search + path prior to importing the ``qemu`` namespace. See + https://docs.python.org/3/library/sys.html#sys.path + +A strong downside to both approaches is that they generally interfere +with static analysis tools being able to locate and analyze the code +being imported. + +Package installation also normally provides executable console scripts, +so that tools like ``qmp-shell`` are always available via $PATH. To +invoke them without installation, you can invoke e.g.: + +``> PYTHONPATH=~/src/qemu/python python3 -m qemu.qmp.qmp_shell`` + +The mappings between console script name and python module path can be +found in ``setup.cfg``. + + Files in this directory ----------------------- -- ``qemu/`` Python package source directory. +- ``qemu/`` Python 'qemu' namespace package source directory. - ``tests/`` Python package tests directory. - ``avocado.cfg`` Configuration for the Avocado test-runner. Used by ``make check`` et al. @@ -50,7 +79,7 @@ Files in this directory - ``PACKAGE.rst`` is used as the README file that is visible on PyPI.org. - ``Pipfile`` is used by Pipenv to generate ``Pipfile.lock``. - ``Pipfile.lock`` is a set of pinned package dependencies that this package - is tested under in our CI suite. It is used by ``make venv-check``. + is tested under in our CI suite. It is used by ``make check-pipenv``. - ``README.rst`` you are here! - ``VERSION`` contains the PEP-440 compliant version used to describe this package; it is referenced by ``setup.cfg``. |