View Full Version : python-virtkey

November 11th, 2007, 06:00 PM
Hey, I'm trying to write a very basic macro (15 lines of code at most) which may grow to new tasks in the future.

After ~1 hour of google searches I concluded that there is no documentation for python-virtkey. I did find the source code, but I don't know C so it wasn't very helpful, can anyone tell me how to get the virtkey module to emulate a keypress? I need it to do spacebar, return, and the letters/numbers

here's the code for the virtkey module: http://codebrowse.launchpad.net/~onboard/virtkey/main/annotate/tortoise%40tortuga-20070809174257-3cho3enck0zg4iq9?file_id=pythonvirtkey.c-20060911161653-c3owb3gyq5x17b53-3

Here's the python I've written so far:

import virtkey
import time



for i in range (1,100,1):
print "loop " + str(i)
keypress(" ") # <-- doesn't work, but doesn't return an error either

Thanks in advance for your help!

November 11th, 2007, 07:42 PM
It always help to mention **what** you want to accomplish, not to assume that the (dead-end) road you picked is the best way to accomplish it.

Looks like you want to send keystokes to your app?

PyGUIUnittest (http://www.pyzine.com/Issue007/Section_Articles/article_PyGUIUnittest.html) or (on Win) SendKeys (http://aspn.activestate.com/ASPN/Cookbook/Python/Recipe/65107) might be better way (and it is package with docs (http://pypi.python.org/pypi/SendKeys/0.3).

Or do you need something different?

November 11th, 2007, 11:07 PM
Looks like you want to send keystokes to your app?

Nah, I was basically trying to send keystrokes to someone else's app. But wanted to be able to use it to control any app. I send the author of virtkey an email to which he replied very quickly. Here's the email I sent, as well as his reply:

My email:

Dear Chris,

I found your module (virtkey) via a google search, and it appears to be exactly what I need. Unfortunately I have been unable to get it to actually emulate any key presses.

is there any documentation? if not, could you explain to me what the virtkey function expects as arguments?

Chris' (the author of python-virtkey) Response:

Sorry, this library has bit-rotted a bit since I wrote it two summers
ago. I was part way through re-writing it but got distracted. It is
used by onboard so you could look at that for examples.

v = virtkey.virtkey()

#where c is the char you want to type.

#where 123 is the x keysym of the key you want to press.

#Where mask is an or-ed combination of the modifiers you want to lock
or latch. Order is the same as in the xkb api.

The other functions are all to do with getting keyboard layouts.

One more thing, Chris mentions how to send the keydown event, but not the keyup. Here's an example that uses the 'press' and 'release' functions of virtkey

import virtkey
import time

# This Example Presses the spacebar once every second for a minute

def press(keyname):
# 'press_unicode()' emulates the key being pressed down
# ord() converts the character to it's unicode value

# The key stays pressed down until you tell virtkey to release
# it with the 'release_unicode()' function. note: you have to specify
# which key to release with the unicode value again


for i in range(60):
# Presses the key
press(" ")

# Wait 1 second

December 27th, 2007, 11:48 PM
Thank you JustAboutRealJAR :):):):)

This helped me too.

It was exactly what I needed.:):)

March 2nd, 2008, 08:30 PM

sorry for the thread-digging, but I want to add something ;)
Here's a working example how to use modifiers for simulating shortcuts:

# simulate CTRL+T
import virtkey
v = virtkey.virtkey()




The Modifier values (e.g. 1<<2) are defined in X11/X.h:

#define ShiftMask (1<<0)
#define LockMask (1<<1)
#define ControlMask (1<<2)
#define Mod1Mask (1<<3)
#define Mod2Mask (1<<4)
#define Mod3Mask (1<<5)
#define Mod4Mask (1<<6)
#define Mod5Mask (1<<7)

You can get the keycodes with the tool xev:

KeyPress event, serial 27, synthetic NO, window 0x4800001,
root 0x8a, subw 0x0, time 1895304872, (715,323), root: (720,371),
state 0x0, keycode 28 (keysym 0x74, t), same_screen YES,
XLookupString gives 1 bytes: (74) "t"
XmbLookupString gives 1 bytes: (74) "t"
XFilterEvent returns: False

I hope that's a help for somebody :)


March 7th, 2008, 12:31 AM
Thanks Fred, this is very useful. :):):)

March 7th, 2008, 05:35 AM
very! I'll be using that info :)

April 3rd, 2008, 07:48 PM

another update:

def simulate_keys(keys):
""" simulate the keys using python-virtkey
:param keys: (modifiers, keysym); returned by keystroke_to_x11
modifiers, key = keys

v = virtkey.virtkey()
if modifiers:
if modifiers:

def keystroke_to_x11(keystroke):
""" convert "CTRL+Shift+T" to (1<<2 | 1<<0, 28)
:param keystroke: The keystroke string.
- can handle at least one 'real' key
- only ctrl, shift and alt supported yet (case-insensitive)
:returns: tuple: (modifiers, keysym)
modifiers = 0
key = ""
splitted = keystroke.split("+")
for stroke in splitted:
lstroke = stroke.lower()
if lstroke == "ctrl" or lstroke == "control":
modifiers |= (1 << 2)
elif lstroke == "shift":
modifiers |= (1 << 0)
elif lstroke == "alt":
modifiers |= (1 << 3) # TODO: right?
else: # is a ordinary key (Only one)
key = gtk.gdk.keyval_from_name(stroke)
return (modifiers, key) (from gestikk (https://launchpad.net/gestikk) ;))

Just use simulate_keys(keystroke_to_x11('CTRL+ALT+A')) - it will simulate it ;) It uses gtk at the moment, because I couldn't find a function similar to gtk.gdk.keyval_from_name - maybe you have an idea? :)


May 14th, 2008, 08:45 PM
I looked through the virtkey C code, but I couldn't tell if there is any way to dictate which tty the key presses go to. Does anyone know if there is a way? I want to be able to send key presses to certain virtual terminals. I need to send it directly to the terminal, so switching to the terminal with something like chvt first won't work.

May 23rd, 2008, 06:52 PM

as far i know, python-virtkey uses the Xtest Extension of the X-Server. I don't think that Xtest is able to send keystrokes to a tty, but I'm not sure.



May 23rd, 2008, 07:04 PM
I had to write a simple kernel module to send the keystrokes to tty. This allowed me to successfully switch VMWare terminals.

November 15th, 2009, 08:27 PM
fred.reichbier, thank you!

After ~1 hour of google searches I concluded that there is no documentation for python-virtkey.
I don't find anything useful too, except you tread. But I do it in 2009 :(
May be i'm wrong