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PYTHON-EVDEV(7) python-evdev PYTHON-EVDEV(7)

NAME

python-evdev - python-evdev Documentation

This package provides bindings to the generic input event interface in Linux. The evdev interface serves the purpose of passing events generated in the kernel directly to userspace through character devices that are typically located in /dev/input/.

This package also comes with bindings to uinput, the userspace input subsystem. Uinput allows userspace programs to create and handle input devices that can inject events directly into the input subsystem.

In other words, python-evdev allows you to read and write input events on Linux. An event can be a key or button press, a mouse movement or a tap on a touchscreen.

FROM AN OS PACKAGE

Python-evdev has been packaged for the following distributions:

Consult the documentation of your OS package manager for installation instructions.

FROM SOURCE

The latest stable version of python-evdev can be installed from pypi, provided that you have a compiler, pip and the Python and Linux development headers installed on your system. Installing these is distribution specific and typically falls into one of the following:

On a Debian compatible OS:

$ apt install python-dev python-pip gcc
$ apt install linux-headers-$(uname -r)


On a Redhat compatible OS:

$ dnf install python-devel python-pip gcc
$ dnf install kernel-headers-$(uname -r)


On Arch Linux and derivatives:

$ pacman -S core/linux-api-headers python-pip gcc


Once all OS dependencies are available, you may install python-evdev using pip, preferably in a [virtualenv]:

# Install globally (not recommended).
$ sudo python3 -m pip install evdev
# Install for the current user.
$ python3 -m pip install --user evdev
# Install in a virtual environment.
$ python3 -m venv abc
$ source abc/bin/activate
$ python3 -m pip install evdev


Specifying header locations

By default, the setup script will look for the input.h and input-event-codes.h [1] header files /usr/include/linux.

You may use the --evdev-headers option to the build_ext setuptools command to the location of these header files. It accepts one or more colon-separated paths. For example:

$ python setup.py build_ext \


    --evdev-headers buildroot/input.h:buildroot/input-event-codes.h \


    --include-dirs  buildroot/ \


    install  # or any other command (e.g. develop, bdist, bdist_wheel)


FROM A BINARY PACKAGE

You may choose to install a precompiled version of python-evdev from pypi. The evdev-binary package provides binary wheels that have been compiled on EL8 against the 4.18.0 kernel headers.

$ python3 -m pip install evdev-binary


While the evdev interface is stable, the precompiled version may not be fully compatible or expose all the features of your running kernel. For best results, it is recommended to use an OS package or to install from source.

[1]
input-event-codes.h is found only in recent kernel versions.

QUICK START

Listing accessible event devices

>>> import evdev
>>> devices = [evdev.InputDevice(path) for path in evdev.list_devices()]
>>> for device in devices:
...    print(device.path, device.name, device.phys)
/dev/input/event1    USB Keyboard        usb-0000:00:12.1-2/input0
/dev/input/event0    USB Optical Mouse   usb-0000:00:12.0-2/input0


NOTE:

If you do not see any devices, ensure that your user is in the correct group (typically input) to have read/write access.


Reading events from a device

>>> import evdev
>>> device = evdev.InputDevice('/dev/input/event1')
>>> print(device)
device /dev/input/event1, name "USB Keyboard", phys "usb-0000:00:12.1-2/input0"
>>> for event in device.read_loop():
...     if event.type == evdev.ecodes.EV_KEY:
...         print(evdev.categorize(event))
... # pressing 'a' and holding 'space'
key event at 1337016188.396030, 30 (KEY_A), down
key event at 1337016188.492033, 30 (KEY_A), up
key event at 1337016189.772129, 57 (KEY_SPACE), down
key event at 1337016190.275396, 57 (KEY_SPACE), hold
key event at 1337016190.284160, 57 (KEY_SPACE), up


Accessing event codes

The evdev.ecodes module provides reverse and forward mappings between the names and values of the event subsystem constants.

>>> from evdev import ecodes
>>> ecodes.KEY_A
... 30
>>> ecodes.ecodes['KEY_A']
... 30
>>> ecodes.KEY[30]
... 'KEY_A'
>>> ecodes.bytype[ecodes.EV_KEY][30]
... 'KEY_A'
# A single value may correspond to multiple event codes.
>>> ecodes.KEY[152]
... ['KEY_COFFEE', 'KEY_SCREENLOCK']


Listing and monitoring input devices

The python-evdev package also comes with a small command-line program for listing and monitoring input devices:

$ python -m evdev.evtest


TUTORIAL

Listing accessible event devices

>>> import evdev
>>> devices = [evdev.InputDevice(path) for path in evdev.list_devices()]
>>> for device in devices:
>>>     print(device.path, device.name, device.phys)
/dev/input/event1    Dell Dell USB Keyboard   usb-0000:00:12.1-2/input0
/dev/input/event0    Dell USB Optical Mouse   usb-0000:00:12.0-2/input0


Listing device capabilities

>>> import evdev
>>> device = evdev.InputDevice('/dev/input/event0')
>>> print(device)
device /dev/input/event0, name "Dell USB Optical Mouse", phys "usb-0000:00:12.0-2/input0"
>>> device.capabilities()
... { 0: [0, 1, 2], 1: [272, 273, 274, 275], 2: [0, 1, 6, 8], 4: [4] }
>>> device.capabilities(verbose=True)
... { ('EV_SYN', 0): [('SYN_REPORT', 0), ('SYN_CONFIG', 1), ('SYN_MT_REPORT', 2)],
...   ('EV_KEY', 1): [('BTN_MOUSE', 272), ('BTN_RIGHT', 273), ('BTN_MIDDLE', 274), ('BTN_SIDE', 275)], ...


Listing device capabilities (devices with absolute axes)

>>> import evdev
>>> device = evdev.InputDevice('/dev/input/event7')
>>> print(device)
device /dev/input/event7, name "Wacom Bamboo 2FG 4x5 Finger", phys ""
>>> device.capabilities()
... { 1: [272, 273, 277, 278, 325, 330, 333] ,
...   3: [(0, AbsInfo(min=0, max=15360, fuzz=128, flat=0)),
...       (1, AbsInfo(min=0, max=10240, fuzz=128, flat=0))] }
>>> device.capabilities(verbose=True)
... { ('EV_KEY', 1): [('BTN_MOUSE', 272), ('BTN_RIGHT', 273), ...],
...   ('EV_ABS', 3): [(('ABS_X', 0), AbsInfo(min=0, max=15360, fuzz=128, flat=0)),
...                   (('ABS_Y', 1), AbsInfo(min=0, max=10240, fuzz=128, flat=0)),] }
>>> device.capabilities(absinfo=False)
... { 1: [272, 273, 277, 278, 325, 330, 333],
...   3: [0, 1, 47, 53, 54, 57] }


Getting and setting LED states

>>> dev.leds(verbose=True)
... [('LED_NUML', 0), ('LED_CAPSL', 1)]
>>> dev.leds()
... [0, 1]
>>> dev.set_led(ecodes.LED_NUML, 1)  # enable numlock
>>> dev.set_led(ecodes.LED_NUML, 0)  # disable numlock


Getting currently active keys

>>> dev.active_keys(verbose=True)
... [('KEY_3', 4), ('KEY_LEFTSHIFT', 42)]
>>> dev.active_keys()
... [4, 42]


Reading events

Reading events from a single device in an endless loop.

>>> from evdev import InputDevice, categorize, ecodes
>>> dev = InputDevice('/dev/input/event1')
>>> print(dev)
device /dev/input/event1, name "Dell Dell USB Keyboard", phys "usb-0000:00:12.1-2/input0"
>>> for event in dev.read_loop():
...     if event.type == ecodes.EV_KEY:
...         print(categorize(event))
... # pressing 'a' and holding 'space'
key event at 1337016188.396030, 30 (KEY_A), down
key event at 1337016188.492033, 30 (KEY_A), up
key event at 1337016189.772129, 57 (KEY_SPACE), down
key event at 1337016190.275396, 57 (KEY_SPACE), hold
key event at 1337016190.284160, 57 (KEY_SPACE), up


Reading events (using asyncio)

NOTE:

This requires Python 3.5+ for the async/await keywords.


>>> import asyncio
>>> from evdev import InputDevice
>>> dev = InputDevice('/dev/input/event1')
>>> async def main(dev):
...     async for ev in dev.async_read_loop():
...         print(repr(ev))
>>> asyncio.run(main(dev))
InputEvent(1527363738, 348740, 4, 4, 458792)
InputEvent(1527363738, 348740, 1, 28, 0)
InputEvent(1527363738, 348740, 0, 0, 0)


Reading events from multiple devices (using select)

>>> from evdev import InputDevice
>>> from select import select
# A mapping of file descriptors (integers) to InputDevice instances.
>>> devices = map(InputDevice, ('/dev/input/event1', '/dev/input/event2'))
>>> devices = {dev.fd: dev for dev in devices}
>>> for dev in devices.values(): print(dev)
device /dev/input/event1, name "Dell Dell USB Keyboard", phys "usb-0000:00:12.1-2/input0"
device /dev/input/event2, name "Logitech USB Laser Mouse", phys "usb-0000:00:12.0-2/input0"
>>> while True:
...    r, w, x = select(devices, [], [])
...    for fd in r:
...        for event in devices[fd].read():
...            print(event)
event at 1351116708.002230, code 01, type 02, val 01
event at 1351116708.002234, code 00, type 00, val 00
event at 1351116708.782231, code 04, type 04, val 458782
event at 1351116708.782237, code 02, type 01, val 01


Reading events from multiple devices (using selectors)

This can also be achieved using the selectors module in Python 3.4:

from evdev import InputDevice
from selectors import DefaultSelector, EVENT_READ
selector = DefaultSelector()
mouse = InputDevice('/dev/input/event1')
keybd = InputDevice('/dev/input/event2')
# This works because InputDevice has a `fileno()` method.
selector.register(mouse, EVENT_READ)
selector.register(keybd, EVENT_READ)
while True:


    for key, mask in selector.select():


        device = key.fileobj


        for event in device.read():


            print(event)


Reading events from multiple devices (using asyncio)

Yet another possibility is the asyncio module from Python 3.4:

import asyncio, evdev
@asyncio.coroutine
def print_events(device):


    while True:


        events = yield from device.async_read()


        for event in events:


            print(device.path, evdev.categorize(event), sep=': ')
mouse = evdev.InputDevice('/dev/input/eventX')
keybd = evdev.InputDevice('/dev/input/eventY')
for device in mouse, keybd:


    asyncio.async(print_events(device))
loop = asyncio.get_event_loop()
loop.run_forever()


Since Python 3.5, the async/await syntax makes this even simpler:

import asyncio, evdev
mouse = evdev.InputDevice('/dev/input/event4')
keybd = evdev.InputDevice('/dev/input/event5')
async def print_events(device):


    async for event in device.async_read_loop():


        print(device.path, evdev.categorize(event), sep=': ')
for device in mouse, keybd:


    asyncio.ensure_future(print_events(device))
loop = asyncio.get_event_loop()
loop.run_forever()


Accessing evdev constants

>>> from evdev import ecodes
>>> ecodes.KEY_A, ecodes.ecodes['KEY_A']
... (30, 30)
>>> ecodes.KEY[30]
... 'KEY_A'
>>> ecodes.bytype[ecodes.EV_KEY][30]
... 'KEY_A'
>>> ecodes.KEY[152]  # a single value may correspond to multiple codes
... ['KEY_COFFEE', 'KEY_SCREENLOCK']


Searching event codes by regex

>>> from evdev import util
>>> res = util.find_ecodes_by_regex(r'(ABS|KEY)_BR(AKE|EAK)')
>>> res
... {1: [411], 3: [10]}
>>> util.resolve_ecodes_dict(res)
... {('EV_KEY', 1): [('KEY_BREAK', 411)], ('EV_ABS', 3): [('ABS_BRAKE', 10)]}


Getting exclusive access to a device

>>> dev.grab()  # become the sole recipient of all incoming input events
>>> dev.ungrab()


This functionality is also available as a context manager.

>>> with dev.grab_context():
...     pass


Associating classes with event types

>>> from evdev import categorize, event_factory, ecodes
>>> class SynEvent:
...     def __init__(self, event):
...         ...
>>> event_factory[ecodes.EV_SYN] = SynEvent


See events for more information.

Injecting input

>>> from evdev import UInput, ecodes as e
>>> ui = UInput()
>>> # accepts only KEY_* events by default
>>> ui.write(e.EV_KEY, e.KEY_A, 1)  # KEY_A down
>>> ui.write(e.EV_KEY, e.KEY_A, 0)  # KEY_A up
>>> ui.syn()
>>> ui.close()


Injecting events (using a context manager)

>>> ev = InputEvent(1334414993, 274296, ecodes.EV_KEY, ecodes.KEY_A, 1)
>>> with UInput() as ui:
...    ui.write_event(ev)
...    ui.syn()


Specifying uinput device options

NOTE:

ecodes.EV_SYN cannot be in the cap dictionary or the device will not be created.


>>> from evdev import UInput, AbsInfo, ecodes as e
>>> cap = {
...     e.EV_KEY : [e.KEY_A, e.KEY_B],
...     e.EV_ABS : [
...         (e.ABS_X, AbsInfo(value=0, min=0, max=255,
...                           fuzz=0, flat=0, resolution=0)),
...         (e.ABS_Y, AbsInfo(0, 0, 255, 0, 0, 0)),
...         (e.ABS_MT_POSITION_X, (0, 128, 255, 0)) ]
... }
>>> ui = UInput(cap, name='example-device', version=0x3)
>>> print(ui)
name "example-device", bus "BUS_USB", vendor "0001", product "0001", version "0003"
event types: EV_KEY EV_ABS EV_SYN
>>> print(ui.capabilities())
{0: [0, 1, 3],


 1: [30, 48],


 3: [(0,  AbsInfo(value=0, min=0, max=0,   fuzz=255, flat=0, resolution=0)),


     (1,  AbsInfo(value=0, min=0, max=0,   fuzz=255, flat=0, resolution=0)),


     (53, AbsInfo(value=0, min=0, max=255, fuzz=128, flat=0, resolution=0))]}
>>> # move mouse cursor
>>> ui.write(e.EV_ABS, e.ABS_X, 20)
>>> ui.write(e.EV_ABS, e.ABS_Y, 20)
>>> ui.syn()


Create uinput device with capabilities of another device

>>> from evdev import UInput, InputDevice
>>> mouse = InputDevice('/dev/input/event1')
>>> keybd = '/dev/input/event2'
>>> ui = UInput.from_device(mouse, keybd, name='keyboard-mouse-device')
>>> ui.capabilities(verbose=True).keys()
dict_keys([('EV_LED', 17), ('EV_KEY', 1), ('EV_SYN', 0), ('EV_REL', 2), ('EV_MSC', 4)])


Create uinput device capable of receiving FF-effects

import asyncio
from evdev import UInput, categorize, ecodes
cap = {


   ecodes.EV_FF:  [ecodes.FF_RUMBLE ],


   ecodes.EV_KEY: [ecodes.KEY_A, ecodes.KEY_B]
}
ui = UInput(cap, name='test-controller', version=0x3)
async def print_events(device):


    async for event in device.async_read_loop():


        print(categorize(event))


        # Wait for an EV_UINPUT event that will signal us that an


        # effect upload/erase operation is in progress.


        if event.type != ecodes.EV_UINPUT:


            continue


        if event.code == ecodes.UI_FF_UPLOAD:


            upload = device.begin_upload(event.value)


            upload.retval = 0


            print(f'[upload] effect_id: {upload.effect.id}, type: {upload.effect.type}')


            device.end_upload(upload)


        elif event.code == ecodes.UI_FF_ERASE:


            erase = device.begin_erase(event.value)


            print(f'[erase] effect_id {erase.effect_id}')


            erase.retval = 0


            device.end_erase(erase)
asyncio.ensure_future(print_events(ui))
loop = asyncio.get_event_loop()
loop.run_forever()


Injecting an FF-event into first FF-capable device found

from evdev import ecodes, InputDevice, ff, list_devices
import time
# Find first EV_FF capable event device (that we have permissions to use).
for name in list_devices():


    dev = InputDevice(name)


    if ecodes.EV_FF in dev.capabilities():


        break
rumble = ff.Rumble(strong_magnitude=0x0000, weak_magnitude=0xffff)
effect_type = ff.EffectType(ff_rumble_effect=rumble)
duration_ms = 1000
effect = ff.Effect(


    ecodes.FF_RUMBLE, -1, 0,


    ff.Trigger(0, 0),


    ff.Replay(duration_ms, 0),


    effect_type
)
repeat_count = 1
effect_id = dev.upload_effect(effect)
dev.write(ecodes.EV_FF, effect_id, repeat_count)
time.sleep(duration_ms / 1000)
dev.erase_effect(effect_id)


Forwarding force-feedback from uinput to a real device

import evdev
from evdev import ecodes as e
# Find first EV_FF capable event device (that we have permissions to use).
for name in evdev.list_devices():


    dev = evdev.InputDevice(name)


    if e.EV_FF in dev.capabilities():


        break
# To ensure forwarding works correctly it is important that `max_effects`
# of the uinput device is <= `dev.ff_effects_count`.
# `from_device()` will do this automatically, but in some situations you may
# want to set the `max_effects` parameter manually, such as when using `Uinput()`.
# `filtered_types` is specified as by default EV_FF events are filtered
uinput = evdev.UInput.from_device(dev, filtered_types=[e.EV_SYN])
# Keeps track of which effects have been uploaded to the device
effects = set()
for event in uinput.read_loop():


    # Handle the special uinput events


    if event.type == e.EV_UINPUT:


        if event.code == e.UI_FF_UPLOAD:


            upload = uinput.begin_upload(event.value)


            # Checks if this is a new effect


            if upload.effect.id not in effects:


                effects.add(upload.effect.id)


                # Setting id to 1 indicates that a new effect must be allocated


                upload.effect.id = -1


            dev.upload_effect(upload.effect)


            upload.retval = 0


            uinput.end_upload(upload)


        elif event.code == e.UI_FF_ERASE:


            erase = uinput.begin_erase(event.value)


            erase.retval = 0


            dev.erase_effect(erase.effect_id)


            effects.remove(erase.effect_id)


            uinput.end_erase(erase)


    # Forward writes to actual rumble device.


    elif event.type == e.EV_FF:


        dev.write(event.type, event.code, event.value)


API REFERENCE

events

This module provides the InputEvent class, which closely resembles the input_event struct defined in linux/input.h:

struct input_event {


    struct timeval time;


    __u16 type;


    __u16 code;


    __s32 value;
};


This module also defines several InputEvent sub-classes that know more about the different types of events (key, abs, rel etc). The event_factory dictionary maps event types to these classes.

Assuming you use the evdev.util.categorize() function to categorize events according to their type, adding or replacing a class for a specific event type becomes a matter of modifying event_factory.

All classes in this module have reasonable str() and repr() methods:

>>> print(event)
event at 1337197425.477827, code 04, type 04, val 458792
>>> print(repr(event))
InputEvent(1337197425L, 477827L, 4, 4, 458792L)
>>> print(key_event)
key event at 1337197425.477835, 28 (KEY_ENTER), up
>>> print(repr(key_event))
KeyEvent(InputEvent(1337197425L, 477835L, 1, 28, 0L))


A generic input event.
Time in seconds since epoch at which event occurred.

Microsecond portion of the timestamp.

Event type - one of ecodes.EV_*.

Event code related to the event type.

Event value related to the event type.

Return event timestamp as a float.


An event generated by a keyboard, button or other key-like devices.






Reference to an InputEvent instance.


A relative axis event (e.g moving the mouse 5 units to the left).
Reference to an InputEvent instance.


A synchronization event. Used as markers to separate events. Events may be separated in time or in space, such as with the multitouch protocol.
Reference to an InputEvent instance.


An absolute axis event (e.g the coordinates of a tap on a touchscreen).
Reference to an InputEvent instance.


A mapping of event types to InputEvent sub-classes. Used by evdev.util.categorize()

eventio

Base class for reading and writing input events.

This class is used by InputDevice and UInput.

  • On, InputDevice it used for reading user-generated events (e.g. key presses, mouse movements) and writing feedback events (e.g. leds, beeps).
  • On, UInput it used for writing user-generated events (e.g. key presses, mouse movements) and reading feedback events (e.g. leds, beeps).

Return the file descriptor to the open event device. This makes it possible to pass instances directly to select.select() and asyncore.file_dispatcher.

Enter an endless select.select() loop that yields input events.

Read and return a single input event as an instance of InputEvent.

Return None if there are no pending input events.


Read multiple input events from device. Return a generator object that yields InputEvent instances. Raises BlockingIOError if there are no available events at the moment.

Decorator that raises EvdevError if there is no write access to the input device.

Inject an input event into the input subsystem. Events are queued until a synchronization event is received.
event (InputEvent) -- InputEvent instance or an object with an event attribute (KeyEvent, RelEvent etc).

Example

>>> ev = InputEvent(1334414993, 274296, ecodes.EV_KEY, ecodes.KEY_A, 1)
>>> ui.write_event(ev)

Inject an input event into the input subsystem. Events are queued until a synchronization event is received.
  • etype -- event type (e.g. EV_KEY).
  • code -- event code (e.g. KEY_A).
  • value -- event value (e.g. 0 1 2 - depends on event type).


Example

>>> ui.write(e.EV_KEY, e.KEY_A, 1) # key A - down
>>> ui.write(e.EV_KEY, e.KEY_A, 0) # key A - up

Inject a SYN_REPORT event into the input subsystem. Events queued by write() will be fired. If possible, events will be merged into an 'atomic' event.


__firstlineno__ = 16

__static_attributes__ = ()

__weakref__
list of weak references to the object


eventio_async

Asyncio coroutine to read and return a single input event as an instance of InputEvent.

Asyncio coroutine to read multiple input events from device. Return a generator object that yields InputEvent instances.

Return an iterator that yields input events. This iterator is compatible with the async for syntax.

__annotations__ = {}

__firstlineno__ = 56

__static_attributes__ = ()



device

Absolute axis information.

A namedtuple with absolute axis information - corresponds to the input_absinfo struct:

Latest reported value for the axis.
int


Specifies minimum value for the axis.
int


Specifies maximum value for the axis.
int


Specifies fuzz value that is used to filter noise from the event stream.
int


Values that are within this value will be discarded by joydev interface and reported as 0 instead.
int


Specifies resolution for the values reported for the axis. Resolution for main axes (ABS_X, ABS_Y, ABS_Z) is reported in units per millimeter (units/mm), resolution for rotational axes (ABS_RX, ABS_RY, ABS_RZ) is reported in units per radian.
int


NOTE:

The input core does not clamp reported values to the [minimum, maximum] limits, such task is left to userspace.


Alias for field number 0

Alias for field number 1

Alias for field number 2

Alias for field number 3

Alias for field number 4

Alias for field number 5

__annotations__ = {'flat': <class 'int'>, 'fuzz': <class 'int'>, 'max': <class 'int'>, 'min': <class 'int'>, 'resolution': <class 'int'>, 'value': <class 'int'>}

__firstlineno__ = 13

__getnewargs__()
Return self as a plain tuple. Used by copy and pickle.

__match_args__ = ('value', 'min', 'max', 'fuzz', 'flat', 'resolution')

Create new instance of AbsInfo(value, min, max, fuzz, flat, resolution)

__orig_bases__ = (<function NamedTuple>,)

__replace__(**kwds)
Return a new AbsInfo object replacing specified fields with new values

__static_attributes__ = ()


Keyboard repeat rate.
Amount of time that a key must be depressed before it will start to repeat (in milliseconds).
int


Keyboard repeat rate in characters per second.
int


Alias for field number 0

Alias for field number 1

__annotations__ = {'delay': <class 'int'>, 'repeat': <class 'int'>}

__firstlineno__ = 63

__getnewargs__()
Return self as a plain tuple. Used by copy and pickle.

__match_args__ = ('delay', 'repeat')

Create new instance of KbdInfo(delay, repeat)

__orig_bases__ = (<function NamedTuple>,)

__replace__(**kwds)
Return a new KbdInfo object replacing specified fields with new values

__static_attributes__ = ()


int


int


int


int


Alias for field number 0

Alias for field number 1

Alias for field number 2

Alias for field number 3

__annotations__ = {'bustype': <class 'int'>, 'product': <class 'int'>, 'vendor': <class 'int'>, 'version': <class 'int'>}

__firstlineno__ = 83

__getnewargs__()
Return self as a plain tuple. Used by copy and pickle.

__match_args__ = ('bustype', 'vendor', 'product', 'version')

Create new instance of DeviceInfo(bustype, vendor, product, version)

__orig_bases__ = (<function NamedTuple>,)

__replace__(**kwds)
Return a new DeviceInfo object replacing specified fields with new values

__static_attributes__ = ()


A linux input device from which input events can be read.
__init__(dev: str | bytes | PathLike)
dev (str|bytes|PathLike) -- Path to input device


Path to input device.

A non-blocking file descriptor to the device file.

A DeviceInfo instance.

The name of the event device.

The physical topology of the device.

The unique identifier of the device.

The evdev protocol version.

The number of force feedback effects the device can keep in its memory.

Return the event types that this device supports as a mapping of supported event types to lists of handled event codes.

Example

>>> device.capabilities()
{ 1: [272, 273, 274],


  2: [0, 1, 6, 8] }

If verbose is True, event codes and types will be resolved to their names.

{ ('EV_KEY', 1): [('BTN_MOUSE', 272),


                  ('BTN_RIGHT', 273),


                  ('BTN_MIDDLE', 273)],


  ('EV_REL', 2): [('REL_X', 0),


                  ('REL_Y', 1),


                  ('REL_HWHEEL', 6),


                  ('REL_WHEEL', 8)] }


Unknown codes or types will be resolved to '?'.

If absinfo is True, the list of capabilities will also include absolute axis information in the form of AbsInfo instances:

{ 3: [ (0, AbsInfo(min=0, max=255, fuzz=0, flat=0)),


       (1, AbsInfo(min=0, max=255, fuzz=0, flat=0)) ]}


Combined with verbose the above becomes:

{ ('EV_ABS', 3): [ (('ABS_X', 0), AbsInfo(min=0, max=255, fuzz=0, flat=0)),


                   (('ABS_Y', 1), AbsInfo(min=0, max=255, fuzz=0, flat=0)) ]}



Get device properties and quirks.

Example

>>> device.input_props()
[0, 5]

If verbose is True, input properties are resolved to their names. Unknown codes are resolved to '?':

[('INPUT_PROP_POINTER', 0), ('INPUT_PROP_POINTING_STICK', 5)]



Return currently set LED keys.

Example

>>> device.leds()
[0, 1, 8, 9]

If verbose is True, event codes are resolved to their names. Unknown codes are resolved to '?':

[('LED_NUML', 0), ('LED_CAPSL', 1), ('LED_MISC', 8), ('LED_MAIL', 9)]



Set the state of the selected LED.

Example

>>> device.set_led(ecodes.LED_NUML, 1)

__eq__(other)
Two devices are equal if their info attributes are equal.

__fspath__()

close() -> None

Grab input device using EVIOCGRAB - other applications will be unable to receive events until the device is released. Only one process can hold a EVIOCGRAB on a device.

WARNING:

Grabbing an already grabbed device will raise an OSError.



Release device if it has been already grabbed (uses EVIOCGRAB).

WARNING:

Releasing an already released device will raise an OSError('Invalid argument').



A context manager for the duration of which only the current process will be able to receive events from the device.

Upload a force feedback effect to a force feedback device.

Erase a force effect from a force feedback device. This also stops the effect.

Get or set the keyboard repeat rate (in characters per minute) and delay (in milliseconds).

__annotations__ = {'fd': 'int', 'name': 'str', 'phys': 'str', 'uniq': 'str', 'version': 'int'}

__firstlineno__ = 103

__hash__ = None

__static_attributes__ = ('_rawcapabilities', 'fd', 'ff_effects_count', 'info', 'name', 'path', 'phys', 'uniq', 'version')

Return currently active keys.

Example

>>> device.active_keys()
[1, 42]

If verbose is True, key codes are resolved to their verbose names. Unknown codes are resolved to '?'. For example:

[('KEY_ESC', 1), ('KEY_LEFTSHIFT', 42)]



Return current AbsInfo for input device axis
axis_num (int) -- EV_ABS keycode (example ecodes.ABS_X)

Example

>>> device.absinfo(ecodes.ABS_X)
AbsInfo(value=1501, min=-32768, max=32767, fuzz=0, flat=128, resolution=0)

Update AbsInfo values. Only specified values will be overwritten.
axis_num (int) -- EV_ABS keycode (example ecodes.ABS_X)

Example

>>> device.set_absinfo(ecodes.ABS_X, min=-2000, max=2000)

You can also unpack AbsInfo tuple that will overwrite all values

>>> device.set_absinfo(ecodes.ABS_Y, *AbsInfo(0, -2000, 2000, 0, 15, 0))


uinput

A userland input device and that can inject input events into the linux input subsystem.
Create an UInput device with the capabilities of one or more input devices.
  • devices (InputDevice|str) -- Varargs of InputDevice instances or paths to input devices.
  • filtered_types (Tuple[event type codes]) -- Event types to exclude from the capabilities of the uinput device.
  • **kwargs -- Keyword arguments to UInput constructor (i.e. name, vendor etc.).



__init__(events: Dict[int, Sequence[int]] | None = None, name: str = 'py-evdev-uinput', vendor: int = 1, product: int = 1, version: int = 1, bustype: int = 3, devnode: str = '/dev/uinput', phys: str = 'py-evdev-uinput', input_props=None, max_effects=96)
  • events (dict) -- Dictionary of event types mapping to lists of event codes. The event types and codes that the uinput device will be able to inject - defaults to all key codes.
  • name -- The name of the input device.
  • vendor -- Vendor identifier.
  • product -- Product identifier.
  • version -- Version identifier.
  • bustype -- Bustype identifier.
  • phys -- Physical path.
  • input_props -- Input properties and quirks.
  • max_effects -- Maximum simultaneous force-feedback effects.


NOTE:

If you do not specify any events, the uinput device will be able to inject only KEY_* and BTN_* event codes.



Uinput device name.

Device vendor identifier.

Device product identifier.

Device version identifier.

Device bustype - e.g. BUS_USB.

Uinput device physical path.

Uinput device node - e.g. /dev/uinput/.

Write-only, non-blocking file descriptor to the uinput device node.

An InputDevice instance for the fake input device. None if the device cannot be opened for reading and writing.

See capabilities.


util

List readable character devices in input_device_dir.

Check if fn is a readable and writable character device.

Categorize an event according to its type.

The event_factory dictionary maps event types to sub-classes of InputEvent. If the event cannot be categorized, it is returned unmodified.


Resolve event codes and types to their verbose names.

Example

>>> resolve_ecodes(ecodes.BTN, [272, 273, 274])
[(['BTN_LEFT', 'BTN_MOUSE'], 272), ('BTN_RIGHT', 273), ('BTN_MIDDLE', 274)]

Resolve event codes and types to their verbose names.
  • typecodemap -- mapping of event types to lists of event codes.
  • unknown -- symbol to which unknown types or codes will be resolved.


Example

>>> resolve_ecodes_dict({ 1: [272, 273, 274] })
{ ('EV_KEY', 1): [('BTN_MOUSE',  272),


                  ('BTN_RIGHT',  273),


                  ('BTN_MIDDLE', 274)] }

If typecodemap contains absolute axis info (instances of AbsInfo ) the result would look like:

>>> resolve_ecodes_dict({ 3: [(0, AbsInfo(...))] })
{ ('EV_ABS', 3L): [(('ABS_X', 0L), AbsInfo(...))] }

ecodes

This modules exposes the integer constants defined in linux/input.h and linux/input-event-codes.h.

Exposed constants:

KEY, ABS, REL, SW, MSC, LED, BTN, REP, SND, ID, EV,
BUS, SYN, FF, FF_STATUS, INPUT_PROP


This module also provides reverse and forward mappings of the names and values of the above mentioned constants:

>>> evdev.ecodes.KEY_A
30
>>> evdev.ecodes.ecodes['KEY_A']
30
>>> evdev.ecodes.KEY[30]
'KEY_A'
>>> evdev.ecodes.REL[0]
'REL_X'
>>> evdev.ecodes.EV[evdev.ecodes.EV_KEY]
'EV_KEY'
>>> evdev.ecodes.bytype[evdev.ecodes.EV_REL][0]
'REL_X'


Keep in mind that values in reverse mappings may point to one or more event codes. For example:

>>> evdev.ecodes.FF[80]
('FF_EFFECT_MIN', 'FF_RUMBLE')
>>> evdev.ecodes.FF[81]
'FF_PERIODIC'


Keys are a combination of all BTN and KEY codes.

Mapping of names to values.

Mapping of event types to other value/name mappings.

SCOPE AND STATUS

Python-evdev exposes most of the more common interfaces defined in the evdev subsystem. Reading and injecting events is well supported and has been tested with nearly all event types.

The basic functionality for reading and uploading force-feedback events is there, but it has not been exercised sufficiently. A major shortcoming of the uinput wrapper is that it does not support force-feedback devices at all (see issue #23).

Some characters, such as : (colon), cannot be easily injected (see issue #7), Translating them into UInput events would require knowing the kernel keyboard translation table, which is beyond the scope of python-evdev. Please look into the following projects if you need more complete or convenient input injection support.

  • python-uinput
  • uinput-mapper
  • pynput
  • pygame (cross-platform)

CHANGELOG

1.9.0 (Feb 08, 2025)

  • Fix for CPATH/C_INCLUDE_PATH being ignored during build.
  • Slightly faster reading of events in device.read() and device.read_one().
  • Fix FreeBSD support.
  • Drop deprecated InputDevice.fn (use InputDevice.path instead).
  • Improve type hint coverage and add a py.typed file to the sdist.

1.8.0 (Jan 25, 2025)

  • Binary wheels are now provided by the evdev-binary package. The package is compiled on manylinux_2_28 against kernel 4.18.
  • The evdev.ecodes module is now generated at install time and contains only constants. This allows type checking and introspection of the evdev.ecodes module, without having to execute it first. The old module is available as evdev.ecodes_runtime. In case generation of the static ecodes.py fails, the install process falls back to using ecodes_runtime.py as ecodes.py.
  • Reverse mappings in evdev.ecodes that point to more than one value are now tuples instead of lists. For example:

>>> ecodes.KEY[153]
('KEY_DIRECTION', 'KEY_ROTATE_DISPLAY')


  • Raise the minimum supported Python version to 3.8.
  • Fix keyboard delay and repeat being swapped (#227).
  • Move the syn() convenience method from InputDevice to EventIO (#224).

1.7.1 (May 8, 2024)

  • Provide fallback value for FF_MAX_EFFECTS, which fixes the build on EL 7 (#219).
  • Add #ifdef guards around UI_GET_SYSNAME to improve kernel compatibility (#218) .
  • Wait up to two seconds for uinput devices to appear. (#215)

1.7.0 (Feb 18, 2024)

  • Respect the CPATH/C_INCLUDE_PATH environment variables during install.
  • Add the uniq address to the string representation of InputDevice.
  • Improved method for finding the device node corresponding to a uinput device (#206).
  • Repository TLC (reformatted with ruff, fixed linting warnings, moved packaging metadata to pyproject.toml etc.).

1.6.1 (Jan 20, 2023)

•
Fix generation of ecodes.c when the path to sys.executable contains spaces.

1.6.0 (Jul 17, 2022)

•
Fix Python 3.11 compatibility (#174).

1.5.0 (Mar 24, 2022)

  • Fix documentation (#163, #160).
  • Re-enable TTY echo at evtest exit (#155).
  • Fix ImportError: sys.meta_path is None, Python is likely shutting down (#154).
  • Closing the input device file descriptor in InputDevice.close() now happens in the main thread, instead of in a new thread (reverts #146).
  • Fix util.find_ecodes_by_regex not working across all supported Python versions (#152).

1.4.0 (Jan 16, 2021)

  • Fix InputDevice.set_absinfo to allow setting parameters to zero.
  • Fix off-by-one in ioctl_EVIOCG_bits, which causes value at the end of the list to not be reported back (#131).
  • Fix set_absinfo to allow setting parameters to zero (#128).
  • Fix leak when returning BlockingIOError from a read (#143).
  • Fix "There is no current event loop in thread" error for non asyncio code (#146).
  • Prevent InputDevice destructor from blocking (#145).
  • Add missing return codes to os.strerror() calls and fix force feedback example in docs (#138).
  • Add the util.find_ecodes_by_regex() helper function.

1.3.0 (Jan 12, 2020)

  • Fix build on 32bit arches with 64bit time_t
  • Add functionality to query device properties. See InputDevice.input_props and the input_props argument to Uinput.
  • KeyEvent received an allow_unknown constructor argument, which determines what will happen when an event code cannot be mapped to a keycode. The default and behavior so far has been to raise KeyError. If set to True, the keycode will be set to the event code formatted as a hex number.
  • Add InputDevice.set_absinfo() and InputDevice.absinfo().
  • Instruct the asyncio event loop to stop monitoring the fd of the input device when the device is closed.

1.2.0 (Apr 7, 2019)

  • Add UInput support for the resolution parameter in AbsInfo. This brings support for the new method of uinput device setup, which was introduced in Linux 4.5 (thanks to @LinusCDE).
  • Vendor and product identifiers can be greater or equal to 0x8000 (thanks @ivaradi).

1.1.2 (Sep 1, 2018)

  • Fix installation on kernels <= 4.4.
  • Fix uinput creation ignoring absinfo settings.

1.1.0 (Aug 27, 2018)

  • Add support for handling force-feedback effect uploads (many thanks to @ndreys).
  • Fix typo preventing ff effects that need left coefficients from working.

1.0.0 (Jun 02, 2018)

  • Prevent Uinput device creation raising Objects/longobject.c:415: bad argument to internal function when a non-complete AbsInfo structure is passed. All missing AbsInfo fields are set to 0.
  • Fix Uinput device creation raising KeyError when a capability filtered by default is not present.
  • The InputDevice.fn attribute was deprecated in favor of InputDevice.path. Using the former will show a DeprecationWarning, but would otherwise continue working as before.
  • Fix InputDevice comparison raising AttributeError due to a non-existant path attribute.
  • Fix asyncio support in Python 3.5+.
  • Uploading FF effect now works both on Python 2.7 and Python 3+.
  • Remove the asyncore example from the tutorial.

0.8.1 (Mar 24, 2018)

  • Fix Python 2 compatibility issue in with Uinput.from_device.
  • Fix minor evdev.evtest formatting issue.

0.8.0 (Mar 22, 2018)

  • Fix InputDevice comparison on Python 2.
  • The device path is now considered when comparing two devices.
  • Fix UInput.from_device not correctly merging the capabilities of selected devices.
  • The list of excluded event types in UInput.from_device is now configurable. For example:

UInput.from_device(dev, filtered_types=(EV_SYN, EV_FF))


In addition, ecodes.EV_FF is now excluded by default.

•
Add a context manager for grabbing access to a device - InputDevice.grab_context. For example:

with dev.grab_context():


    pass


•
Add the InputDevice.uniq attribute, which contains the unique identifier of the device. As with phys, this attribute may be empty (i.e. '').

0.7.0 (Jun 16, 2017)

•
InputDevice now accepts objects that support the path protocol. For example:

pth = pathlib.Path('/dev/input/event0')
dev = evdev.InputDevice(pth)


  • Support path protocol in InputDevice. This means that InputDevice instances can be passed to callers that expect a os.PathLike object.
  • Exceptions raised during InputDevice.async_read() (and similar) are now handled properly (i.e. an exception is set on the returned future instead of leaking that exception into the event loop) (Fixes #67).

0.6.4 (Oct 07, 2016)

•
Exclude ecodes.c from source distribution (Fixes #63).

0.6.3 (Oct 06, 2016)

•
Add the UInput.from_device class method, which allows uinput device to be created with the capabiltiies of one or more existing input devices:

ui = UInput.from_device('/dev/input1', '/dev/input2', **constructor_kwargs)


•
Add the build_ecodes distutils command, which generates the ecodes.c extension module. The new way of overwriting the evdev header locations is:

python setup.py build \


  build_ecodes --evdev-headers path/input.h:path/input-event-codes.h \


  build_ext --include-dirs  path/ \


  install


The build* and install commands no longer have to be part of the same command-line (i.e. running install will reuse the outputs of the last build).


0.6.1 (Jun 04, 2016)

  • Disable tty echoing while evtest is running.
  • Allow evtest to listen to more than one devices.
  • The setup.py script now allows the location of the input header files to be overwritten. For example:

python setup.py build_ext \


  --evdev-headers path/input.h:path/input-event-codes.h \


  --include-dirs  path/ \


  install



0.6.0 (Feb 14, 2016)

  • Asyncio and async/await support (many thanks to @paulo-raca).
  • Add the ability to set the phys property of uinput devices (thanks @paulo-raca).
  • Add a generic InputDevice.set() method (thanks @paulo-raca).
  • Distribute the evtest script along with evdev.
  • Fix issue with generating ecodes.c in recent kernels (>= 4.4.0).
  • Fix absinfo item indexes in UInput.uinput_create() (thanks @forsenonlhaimaisentito).
  • More robust comparison of InputDevice objects (thanks @isia).

0.5.0 (Jun 16, 2015)

•
Write access to the input device is no longer mandatory. Evdev will first try to open the device for reading and writing and fallback to read-only. Methods that require write access (e.g. set_led()) will raise EvdevError if the device is open only for reading.

0.4.7 (Oct 07, 2014)

•
Fallback to distutils if setuptools is not available.

0.4.6 (Oct 07, 2014)

  • Rework documentation and docstrings once more.
  • Fix install on Python 3.4 (works around issue21121).
  • Fix ioctl() requested buffer size (thanks Jakub Wojciech Klama).

0.4.5 (Jul 06, 2014)

  • Add method for returning a list of the currently active keys - InputDevice.active_keys() (thanks @spasche).
  • Fix a potential buffer overflow in ioctl_capabilities() (thanks @spasche).

0.4.4 (Jun 04, 2014)

•
Calling InputDevice.read_one() should always return None, when there is nothing to be read, even in case of a EAGAIN errno (thanks JPP).

0.4.3 (Dec 19, 2013)

  • Silence OSError in destructor (thanks @polyphemus).
  • Make InputDevice.close() work in cases in which stdin (fd 0) has been closed (thanks @polyphemus).

0.4.2 (Dec 13, 2013)

  • Rework documentation and docstrings.
  • Call InputDevice.close() from InputDevice.__del__().

0.4.1 (Jul 24, 2013)

•
Fix reference counting in InputDevice.device_read(), InputDevice.device_read_many() and ioctl_capabilities().

0.4.0 (Jul 01, 2013)

  • Add FF_* and FF_STATUS codes to ecodes() (thanks @bgilbert).
  • Reverse event code mappings (ecodes.{KEY,FF,REL,ABS} and etc.) will now map to a list of codes, whenever a value corresponds to multiple codes:

>>> ecodes.KEY[152]
... ['KEY_COFFEE', 'KEY_SCREENLOCK']
>>> ecodes.KEY[30]
... 'KEY_A'


  • Set the state of a LED through InputDevice.set_led() (thanks @accek).
  • Open InputDevice.fd in O_RDWR mode from now on.
  • Fix segfault in InputDevice.device_read_many() (thanks @bgilbert).

0.3.3 (May 29, 2013)

  • Raise IOError from InputDevice.device_read() and InputDevice.device_read_many() when InputDevice.read() fails.
  • Several stability and style changes (thank you debian code reviewers).

0.3.2 (Apr 05, 2013)

•
Fix vendor id and product id order in DeviceInfo() (thanks @kived).

0.3.1 (Nov 23, 2012)

  • InputDevice.read() will return an empty tuple if the device has nothing to offer (instead of segfaulting).
  • Exclude unnecessary package data in sdist and bdist.

0.3.0 (Nov 06, 2012)

  • Add ability to set/get auto-repeat settings with EVIOC{SG}REP.
  • Add InputDevice.version() - the value of EVIOCGVERSION.
  • Add InputDevice.read_loop().
  • Add InputDevice.grab() and InputDevice.ungrab() - exposes EVIOCGRAB.
  • Add InputDevice.leds() - exposes EVIOCGLED.
  • Replace DeviceInfo class with a namedtuple.
  • Prevent InputDevice.read_one() from skipping events.
  • Rename AbsData to AbsInfo (as in struct input_absinfo).

0.2.0 (Aug 22, 2012)

  • Add the ability to set arbitrary device capabilities on uinput devices (defaults to all EV_KEY ecodes).
  • Add UInput.device which is an open InputDevice to the input device that uinput 'spawns'.
  • Add UInput.capabilities() which is just a shortcut to UInput.device.capabilities().
  • Rename UInput.write() to UInput.write_event().
  • Add a simpler UInput.write(type, code, value)() method.
  • Make all UInput() constructor arguments optional (default device name is now py-evdev-uinput).
  • Add the ability to set absmin, absmax, absfuzz and absflat when specifying the uinput device's capabilities.
  • Remove the nophys argument - if a device fails the EVIOCGPHYS ioctl, phys will equal the empty string.
  • Make InputDevice.capabilities() perform a EVIOCGABS ioctl for devices that support EV_ABS and return that info wrapped in an AbsData namedtuple.
  • Split ioctl_devinfo into ioctl_devinfo and ioctl_capabilities.
  • Split UInput.uinput_open() to UInput.uinput_open() and UInput.uinput_create()
  • Add more uinput usage examples and documentation.
  • Rewrite uinput tests.
  • Remove mouserel and mouseabs from UInput.
  • Tie the sphinx version and release to the distutils version.
  • Set 'methods-before-attributes' sorting in the docs.
  • Remove KEY_CNT and KEY_MAX from ecodes.keys().

0.1.1 (May 18, 2012)

  • Add events.keys, which is a combination of all BTN_ and KEY_ event codes.
  • ecodes.c was not generated when installing through pip.

0.1.0 (May 17, 2012)

Initial Release

This package is released under the terms of the Revised BSD License.

AUTHOR

Georgi Valkov

COPYRIGHT

2012-2025, Georgi Valkov and contributors

March 1, 2025 1.9.1