upower_json.py

import dbus
import json

#  https://upower.freedesktop.org/docs/Device.html
PROPERTIES_MAP = {
    "Type": {
        0: "Unknown",
        1: "Line Power",
        2: "Battery",
        3: "Ups",
        4: "Monitor",
        5: "Mouse",
        6: "Keyboard",
        7: "Pda",
        8: "Phone",
    },
    "State": {
        0: "Unknown",
        1: "Charging",
        2: "Discharging",
        3: "Empty",
        4: "Fully charged",
        5: "Pending charge",
        6: "Pending discharge",
    },
    "Technology": {
        0: "Unknown",
        1: "Lithium ion",
        2: "Lithium polymer",
        3: "Lithium iron phosphate",
        4: "Lead acid",
        5: "Nickel cadmium",
        6: "Nickel metal hydride",
    },
    "WarningLevel": {
        0: "Unknown",
        1: "None",
        2: "Discharging",
        3: "Low",
        4: "Critical",
        5: "Action",
    },
    "BatteryLevel": {
        0: "Unknown",
        1: "None",
        3: "Low",
        4: "Critical",
        6: "Normal",
        7: "High",
        8: "Full",
    },
}

#  https://dbus.freedesktop.org/doc/dbus-python/tutorial.html#basic-types
NORMALIZE_TYPE_MAP = {
    dbus.Boolean: bool,
    dbus.Int16: int,
    dbus.UInt16: int,
    dbus.Int32: int,
    dbus.UInt32: int,
    dbus.Int64: int,
    dbus.UInt64: int,
    dbus.Double: float,
    dbus.String: str,
}

def get_devices(bus):
    obj = bus.get_object(bus_name="org.freedesktop.UPower", object_path="/org/freedesktop/UPower")
    devices = obj.EnumerateDevices(dbus_interface="org.freedesktop.UPower")
    return devices

def get_device_properties(bus, device_object_path):
    obj = bus.get_object(bus_name="org.freedesktop.UPower", object_path=device_object_path)
    interface = dbus.Interface(object=obj, dbus_interface="org.freedesktop.DBus.Properties")
    properties = interface.GetAll("org.freedesktop.UPower.Device")
    return properties

def get_all():
    result = dbus.Array()
    bus = dbus.SystemBus()
    devices = get_devices(bus)
    for device in devices:
        device_properties = get_device_properties(bus, device)
        result.append(device_properties)
    return result

def normalize(obj):
    if type(obj) in NORMALIZE_TYPE_MAP:
        return NORMALIZE_TYPE_MAP[type(obj)](obj)
    if isinstance(obj, dbus.Array):
        return [normalize(v) for v in obj]
    if isinstance(obj, dbus.Dictionary):
        result = {}
        for k, v in obj.items():
            if k in PROPERTIES_MAP:
                result[normalize(k)] = PROPERTIES_MAP[k].get(v, "Unknown")
            else:
                result[normalize(k)] = normalize(v)
        return result
    return obj

def main():
    devices = get_all()
    print(json.dumps(normalize(devices)))

if __name__ == "__main__":
    main()