# import
import pyudev
#pyudev version
print pyudev.__version__
#udev version
# http://lwn.net/Articles/490413/
print pyudev.udev_version()


# create a context object we will use throughout this notebook
context = pyudev.Context()

# list all the subsystems
device_subsystems=[]
for device in context.list_devices():    
    device_subsystems.append(device.subsystem)
    
print set(device_subsystems)

# list devices in the network subsystem
for net_dev in context.list_devices(subsystem='net'):
    print net_dev

# access CPU device properties
for dev in context.list_devices(subsystem='cpu'):
    print cpu_dev.device_path      
    attributes = dev.attributes
    for a in attributes:
        try:
            print a, attributes[a]
        except KeyError:
            pass
    
    # allow a line before the next device
    print

# access the properties of the devices in the graphics subsystem
for dev in context.list_devices(subsystem='graphics'):
    print dev.device_path
    
    attributes = dev.attributes
    for a in attributes:
        try:
            print a, attributes[a]
        except KeyError:
            pass
    
    # allow a line before the next device
    print

# access properties from the USB sub system

for dev in context.list_devices(subsystem='usb'):
    print dev.device_path
    
    attributes = dev.attributes
    for a in attributes:
        try:
            print a, attributes[a]
        except KeyError:
            pass
    
    print
    

# access properties from the sound sub system

for dev in context.list_devices(subsystem='usb'):
    print dev.device_path
    
    attributes = dev.attributes
    for a in attributes:
        try:
            print a, attributes[a]
        except KeyError:
            pass
    
    print

#Device monitoring demo
#this is blocking
#for async monitoring, see http://pyudev.readthedocs.org/en/latest/guide.html#asynchronous-monitoring
monitor = pyudev.Monitor.from_netlink(context)
# monitoring the USB HID subsystem
monitor.filter_by('hid')

for device in iter(monitor.poll, None):
    print device, device.action

# i plugged out and then in a USB keyboard
# The traceback is due to me manually ending the polling loop
# also notice the "add" action after the tracback

# create a device entry directly
device = pyudev.Device.from_path(context, '/sys/devices/system/cpu/cpu0')
for a in device.attributes:
    print a