how do you skip inputs if nothing is entered?

[lllllIllIlllI]

Hi
My question is: i made a program that counts up and up continuously in the background but i want it to print what number it is up to when you press a certain button such as ENTER. I have tried using raw_inputs() but all that happens is it keeps waiting every time for an input rather then just continuing counting like it is meant to. Any help would be greatly appreciated.

[sneekula]

If you are using Windows you can do this:

# get the character of a key pressed (no return key needed)
# works only in the command window and with Windows OS
from msvcrt import getch

print "press a char key (escape key to exit)"

while True:
    z = getch()
    # escape key to exit
    if ord(z) == 27:
        break
    print z,

There is also a way to do it with Tkinter running in the background.

[lllllIllIlllI]

That dosent really solve my problem

# get the character of a key pressed (no return key needed)
# works only in the command window and with Windows OS
from msvcrt import getch

print "press a char key (escape key to exit)"
z=0
x=0
while True:
    x=x+1
    z = getch()
    print ord(z)
    # escape key to exit
    if ord(z) == 27:
        break
    print z,x

what i want is x to keep counting wether a button has been pressed or not and when a button is pressed it shows how high x is. for example the first time you press enter x might print as 12 the next at 124 and so on but inbetween buttons being pressed nothing is printed

[a1eio]

Well you could just use a Thread object to do the counting for you and then in your main program everytime the user enters a key, you just call a function of the Thread object counting that returns it's current value.

The example below might help.

# counterTest.py, a1eio

import threading

# create a thread object that will do the counting in a separate thread
class counter(threading.Thread):
    def __init__(self, value, increment):
        threading.Thread.__init__(self) # init the thread
        self.value = value # initial value
        self.increment = increment # amount to increment
        self.alive = False # controls the while loop in the run command

    def run(self): # this is the main function that will run in a separate thread
        self.alive = True
        while self.alive:
            self.value += self.increment # do the counting

    def peek(self): # return the current value
        return self.value

    def finish(self): # close the thread, return final value
        self.alive = False # stop the while loop in 'run'
        return self.value # return value

def Main():
    # create separate instances of the counter
    counterA = counter(1, 1) #initial value, increment
    counterB = counter(1, 2) #initial value, increment
    counterC = counter(1, 3) #initial value, increment

    # start each counter
    counterA.start()
    counterB.start()
    counterC.start()

    print "Enter A, B, or C to view counters\nEnter Q to quit"
    while True:
        Input = raw_input("> ").upper() # get input

        if Input == 'A':
            print 'CounterA: ', counterA.peek() # print counterA's value
        elif Input == 'B':
            print 'CounterB: ', counterB.peek() # print counterB's value
        elif Input == 'C':
            print 'CounterC: ', counterC.peek() # print counterC's value
    
        elif Input == 'Q': # if user entered q or Q, program quits
            # call the function that finishes each counter and print the returned value
            print 'CounterA: ', counterA.finish()
            print 'CounterB: ', counterB.finish()
            print 'CounterC: ', counterC.finish()
            return # exit the Main function

        else:
            pass

if __name__ == '__main__':
    Main()

Output

Enter A, B, or C to view counters
Enter Q to quit
> a
CounterA:  428610
> b
CounterB:  1359943
> c
CounterC:  4064077
> q
CounterA:  1841495
CounterB:  2832249
CounterC:  5452621

[lllllIllIlllI]

Thanks!!
That is exactly what i was looking for!
great ideas and it works really well.
Problem Solved!

[vegaseat]

Very nice example of threading a1eio!

Could you do all of us a favor and contribute that to the Python code snippets? It would be much appreciated!

My appologies, but just a hint to stay in the Python code guidelines, in the snippet could you start your class with an upper case letter and your function Main() with a lower case letter? That would make it perfect!

[a1eio]

Thanks.
Yea not a problem i'll put it there now.

And I will look up the python code guidlines thing (i have heard of it before to be honest) i'm just lazy hehe.