pyudev.core module¶
Core types and functions of pyudev.
- class pyudev.core.Context¶
Bases:
objectA device database connection.
This class represents a connection to the udev device database, and is really the central object to access udev. You need an instance of this class for almost anything else in pyudev.
This class itself gives access to various udev configuration data (e.g.
sys_path,device_path), and provides device enumeration (list_devices()).Instances of this class can directly be given as
udev *to functions wrapped throughctypes.- property device_path¶
The device directory path defaulting to
/devas unicode string.
- list_devices(**kwargs)¶
List all available devices.
The arguments of this method are the same as for
Enumerator.match(). In fact, the arguments are simply passed straight to methodmatch().This function creates and returns an
Enumeratorobject, that can be used to filter the list of devices, and eventually retrieveDeviceobjects representing matching devices.Changed in version 0.8: Accept keyword arguments now for easy matching.
- property log_priority¶
The logging priority of the interal logging facitility of udev as integer with a standard
syslogpriority. Assign to this property to change the logging priority.UDev uses the standard
syslogpriorities. Constants for these priorities are defined in thesyslogmodule in the standard library:>>> import syslog >>> context = pyudev.Context() >>> context.log_priority = syslog.LOG_DEBUG
Added in version 0.9.
- property run_path¶
The run runtime directory path defaulting to
/runas unicode string.Required udev version: 167
Added in version 0.10.
- property sys_path¶
The
sysfsmount point defaulting to/sys'as unicode string.
- class pyudev.core.Enumerator(context)¶
Bases:
objectA filtered iterable of devices.
To retrieve devices, simply iterate over an instance of this class. This operation yields
Deviceobjects representing the available devices.Before iteration the device list can be filtered by subsystem or by property values using
match_subsystem()andmatch_property(). Multiple subsystem (property) filters are combined using a logical OR, filters of different types are combined using a logical AND. The following filter for instance:devices.match_subsystem('block').match_property( 'ID_TYPE', 'disk').match_property('DEVTYPE', 'disk')
means the following:
subsystem == 'block' and (ID_TYPE == 'disk' or DEVTYPE == 'disk')
Once added, a filter cannot be removed anymore. Create a new object instead.
Instances of this class can directly be given as given
udev_enumerate *to functions wrapped throughctypes.- match(**kwargs)¶
Include devices according to the rules defined by the keyword arguments. These keyword arguments are interpreted as follows:
The value for the keyword argument
subsystemis forwarded tomatch_subsystem().The value for the keyword argument
sys_nameis forwared tomatch_sys_name().The value for the keyword argument
tagis forwared tomatch_tag().The value for the keyword argument
parentis forwared tomatch_parent().All other keyword arguments are forwareded one by one to
match_property(). The keyword argument itself is interpreted as property name, the value of the keyword argument as the property value.
All keyword arguments are optional, calling this method without no arguments at all is simply a noop.
Return the instance again.
Added in version 0.8.
Changed in version 0.13: Add
parentkeyword.
- match_attribute(attribute, value, nomatch=False)¶
Include all devices, whose
attributehas the givenvalue.attributeis either a unicode string or a byte string, containing the name of a sys attribute to match.valueis an attribute value, being one of the following types:int(),bool()A byte string
Anything convertable to a unicode string (including a unicode string itself)
If
nomatchisTrue(default isFalse), the match is inverted: A device is include if theattributedoes not match the givenvalue.Note
If
nomatchisTrue, devices which do not have the givenattributeat all are also included. In other words, withnomatch=Truethe givenattributeis not guaranteed to exist on all returned devices.Return the instance again.
- match_is_initialized()¶
Include only devices, which are initialized.
Initialized devices have properly set device node permissions and context, and are (in case of network devices) fully renamed.
Currently this will not affect devices which do not have device nodes and are not network interfaces.
Return the instance again.
See also
Device.is_initializedRequired udev version: 165
Added in version 0.8.
- match_parent(parent)¶
Include all devices on the subtree of the given
parentdevice.The
parentdevice itself is also included.parentis aDevice.Return the instance again.
Required udev version: 172
Added in version 0.13.
- match_property(prop, value)¶
Include all devices, whose
prophas the givenvalue.propis either a unicode string or a byte string, containing the name of the property to match.valueis a property value, being one of the following types:int()bool()A byte string
Anything convertable to a unicode string (including a unicode string itself)
Return the instance again.
- match_subsystem(subsystem, nomatch=False)¶
Include all devices, which are part of the given
subsystem.subsystemis either a unicode string or a byte string, containing the name of the subsystem. IfnomatchisTrue(default isFalse), the match is inverted: A device is only included if it is not part of the givensubsystem.Note that, if a device has no subsystem, it is not included either with value of
nomatchTrue or with value ofnomatchFalse.Return the instance again.
- match_sys_name(sys_name)¶
Include all devices with the given name.
sys_nameis a byte or unicode string containing the device name.Return the instance again.
Added in version 0.8.
- match_tag(tag)¶
Include all devices, which have the given
tagattached.tagis a byte or unicode string containing the tag name.Return the instance again.
Required udev version: 154
Added in version 0.6.