sdbus 0.14.0

Modern Python D-Bus library. Based on sd-bus from libsystemd.

Modern Python library for D-Bus

Features:

• Asyncio and blocking calls.
• Type hints. (mypy --strict compatible)
• No Python 2 legacy.
• Based on fast sd-bus from systemd. (also supports elogind)
• Unified client/server interface classes. Write interface once!
• D-Bus methods can have keyword and default arguments.

See the documentation for tutorial and API reference.

List of implemented interfaces

• D-Bus (built-in)
• Freedesktop Notifications
• Network Manager
• Freedesktop Secrets

More incoming. (systemd, Bluez, screen saver... )

Community interfaces

• systemd (by @bernhardkaindl)
• modemmanager (by @zhanglongqi)

Stability

Python-sdbus is under development and its API is not stable. Generally anything documented in the official documentation is considered stable but might be deprecated. Using deprecated feature will raise a warning and the feature will be eventually removed.

See the deprecations list.

If there is a feature that is not documented but you would like to use please open a new issue.

Requirements

Binary package from PyPI

• Python 3.9 or higher.
• x86_64, aarch64 or armv7l architecture.
• glibc 2.28 or higher. (Debian 10+, Ubuntu 18.10+, CentOS/RHEL 8+)
• pip 20.3 or higher.

libsystemd is statically linked and is not required to be installed on the system.

Pass --only-binary ':all:' to pip to ensure that it installs binary package.

i686, ppc64le and s390x can be supported if there is a demand. Please open an issue if you are interested in those platforms.

Source package or compiling from source

• Python 3.9 or higher.
• Python headers. (python3-dev package on ubuntu)
• GCC.
• libsystemd or libelogind
• libsystemd headers. (libsystemd-dev package on ubuntu)
• Python setuptools.
• pkg-config

Systemd version should be higher than 246.

Optional dependencies

• Jinja2 for code generator.
• Sphinx for autodoc.

Installation

PyPI

URL: https://pypi.org/project/sdbus/

pip install --only-binary ':all:' sdbus

AUR

URL: https://aur.archlinux.org/packages/python-sdbus-git/

Example code

Interface example_interface.py file:

from sdbus import (DbusInterfaceCommonAsync, dbus_method_async,
                   dbus_property_async, dbus_signal_async)

# This is file only contains interface definition for easy import
# in server and client files

class ExampleInterface(
    DbusInterfaceCommonAsync,
    interface_name='org.example.interface'
):
    @dbus_method_async(
        input_signature='s',
        result_signature='s',
    )
    async def upper(self, string: str) -> str:
        return string.upper()

    @dbus_property_async(
        property_signature='s',
    )
    def hello_world(self) -> str:
        return 'Hello, World!'

    @dbus_signal_async(
        signal_signature='i'
    )
    def clock(self) -> int:
        raise NotImplementedError

Server example_server.py file:

from asyncio import new_event_loop, sleep
from random import randint
from time import time

from example_interface import ExampleInterface

from sdbus import request_default_bus_name_async

loop = new_event_loop()

export_object = ExampleInterface()


async def clock() -> None:
    """
    This coroutine will sleep a random time and emit
    a signal with current clock
    """
    while True:
        await sleep(randint(2, 7))  # Sleep a random time
        current_time = int(time())  # The interface we defined uses integers
        export_object.clock.emit(current_time)


async def startup() -> None:
    """Perform async startup actions"""
    # Acquire a known name on the bus
    # Clients will use that name to address this server
    await request_default_bus_name_async('org.example.test')
    # Export the object to D-Bus
    export_object.export_to_dbus('/')


loop.run_until_complete(startup())
task_clock = loop.create_task(clock())
loop.run_forever()

Client example_client.py file:

from asyncio import new_event_loop

from example_interface import ExampleInterface

# Create a new proxied object
example_object = ExampleInterface.new_proxy('org.example.test', '/')


async def print_clock() -> None:
    # Use async for loop to print clock signals we receive
    async for x in example_object.clock:
        print('Got clock: ', x)


async def call_upper() -> None:
    s = 'test string'
    s_after = await example_object.upper(s)

    print('Initial string: ', s)
    print('After call: ', s_after)


async def get_hello_world() -> None:
    print('Remote property: ', await example_object.hello_world)

loop = new_event_loop()

# Always bind your tasks to a variable
task_upper = loop.create_task(call_upper())
task_clock = loop.create_task(print_clock())
task_hello_world = loop.create_task(get_hello_world())

loop.run_forever()

License

Python-sdbus is licensed under LGPL-2.1-or-later.

The LGPL license is an extension of GPL license therefore both licenses' texts are required.