need help about time.sleep, timer

[Bengt Richter]

On Mon, 21 Nov 2005 10:35:20 +0200, Sinan Nalkaya <erchamion.beren at gmail.com> wrote:

>Dennis Lee Bieber wrote:
>
>>On Fri, 18 Nov 2005 22:45:37 -0500, Peter Hansen <peter at engcorp.com>
>>declaimed the following in comp.lang.python:
>>
>>  
>>
>>>It's quite unclear whether the last part, above, is one of your 
>>>*requirements*, or a description of a problem you are having with your 
>>>current approach.  Do you *want* it to wait forever if you don't enter 
>>>anthing?
>>>
>>>    
>>>
>>	As I understand it, he (?) wants to accumulate characters to be
>>passed to a certain function -- but the function is not to be invoked
>>until after a time period has expired; the time period resetting on each
>>character entered.
>>
>>	Something I'd do with threads, queues, and sleep...
>>
>>PSEUDOCODE
>>
>>thread1:
>>	while not Shutdown:
>>		ch = getChar()
>>		q.put(ch)
>>
>>
>>thread2: #or main
>>	while not Shutdown:
>>		chars = []
>>		while True:
>>			sleep(max_interval)
>>			if q.empty(): break #no input since start of sleep
>>			while not q.empty():	#collect all input from sleep
>>				chars.append(q.get())
>>		inp = "".join(chars)
>>		function(inp)
>>
>>
>>
>>  
>>
>i appreciate your comments and ideas. Dennis told exactly what i tried 
>to say :), code seems to be fine but during sleep action i think the 
>above code does not execute
>
>if q.empty(): break #no input since start of sleep
>			while not q.empty():
>				chars.append(q.get())
>
>i need something, while sleeping, executes the function that waits for 
>input from keyboard.
>i imagined something like that, i have a queu, it both stores the keys 
>that pressed and pressing times of these keys, then i`ll proccess these 
>times. here is scenario
>input : 5
>after 10 seconds later input 5 is being proccessed
>return back to main function
>input : 1
>after 5 seconds , other input 5
>after 5 more seconds , 15 is being proccessed
>Thanks.

If I understand, you really don't want to sleep, you want to wait a max time of 5 seconds
for a character. You can get that from a queue.get(True,5) hence, you could try the
following as a start (untested, and I don't have much experience with python threading,
so will wait for bug reports ;-)

Note that it uses getch for input, which doesn't echo. (Change to getche if you want echo)
You can run this from the command line with one arg: the number of seconds you want to
have the test continue. At the end of that time it will set the Shutdown event, and
thread2 should empty the queue and wait 5 seconds and then do its last function call and
see the shutdown event.

----< tqinp.py >-----------------------------------------------------------------------
# tqinp.py -- test queued input of unechoed character input until a 5-second delay
import threading
import Queue
import msvcrt
queue = Queue.Queue(10) # 2 is prob enough for this thing
Shutdown = threading.Event()

def getChar(): return msvcrt.getch() # blocks
def function(s): print 'function(%r)'%s

def thread1(q):
    while not Shutdown.isSet():
        ch = getChar()
        q.put(ch)

def thread2(q): #or main
    while not Shutdown.isSet():
        chars = ''
        try:
            while True: chars += q.get(True, 5)
        except Queue.Empty, e:
            print 'No input for 5 seconds. Using %r'%chars
        function(chars)

import time
def test(trial_time):
    thr1 = threading.Thread(target=thread1, args=(queue,))
    thr1.start()
    thr2 = threading.Thread(target=thread2, args=(queue,))
    thr2.start()
    t0 = time.clock()
    time.sleep(trial_time)
    print 'Ending trial after %s seconds' % (time.clock()-t0)
    Shutdown.set()

if __name__ == '__main__':
    import sys
    if not sys.argv[1:]: raise SystemExit,'Usage: python tqinp.py'
    test(float(sys.argv[1]))
---------------------------------------------------------------------------------------

Ok, in the following I'll type 123 <pause 5> abc <pause to let it die>

[ 5:40] C:\pywk\clp\threadstuff>py24 tqinp.py 15
No input for 5 seconds. Using '123'
function('123')
No input for 5 seconds. Using 'abc'
function('abc')
Ending trial after 14.9948775627 seconds
No input for 5 seconds. Using ''
function('')

[ 5:41] C:\pywk\clp\threadstuff>

Except it didn't die until I hit another key to let thread1 loop and see its Shutdown test.
But this is alpha 0.01, so you can fix that various ways. Or maybe get the real requirements down ;-)
HTH
(once I get it posted -- news reads ok now but news server is not accepting posts.
I suspect they do system-hogging chores Sun night wee hours ;-/

Regards,
Bengt Richter