CODEWITHSUNDEEP
pythonloops
Dritz
Dritz

Reputation: 117

Run a loop while waiting for a user input

I want to run a loop in my script while the user has not input anything. But when they have input something I want the loop to break.

The issue I am currently having is that when using the input() function, the script will stop and wait for an input, but I want to run another part of the script while waiting for the user input.

I have tried using try: with a raw_input():

while True:
    try:
        print('SCAN BARCODE')
        userInput= raw_input()
        #doing something with input
    except:
        #run this while there is no input

With this, I find that whatever is in the except: will always run, but it will not run try: even when there is a user input. If I change raw_input() to input() the script just waits at input() and doesn't run anything in the except:.

How do I achieve what I am after?

Upvotes: 7

Views: 15850

Answers (3)

Abhishek Kumar
Abhishek Kumar

Reputation: 73

It simple bro u use flag boolean values 

Flag = True
while Flag:
    try:
        Print('scan bar code')
        User_inp = input()
        if User_inp != '':
            Flag = False
    Except:
        Print('except part')

Upvotes: 2

kederrac
kederrac

Reputation: 17322

you can use python threads:

from threading import Thread
import time

thread_running = True


def my_forever_while():
    global thread_running

    start_time = time.time()

    # run this while there is no input
    while thread_running:
        time.sleep(0.1)

        if time.time() - start_time >= 5:
            start_time = time.time()
            print('Another 5 seconds has passed')


def take_input():
    user_input = input('Type user input: ')
    # doing something with the input
    print('The user input is: ', user_input)


if __name__ == '__main__':
    t1 = Thread(target=my_forever_while)
    t2 = Thread(target=take_input)

    t1.start()
    t2.start()

    t2.join()  # interpreter will wait until your process get completed or terminated
    thread_running = False
    print('The end')

In my example you have 2 threads, the first thread is up and executes code until you have some input from the user, thread 2 is waiting for some input from the user. After you got the user input thread 1 and 2 will stop.

Upvotes: 11

flagboy firelight
flagboy firelight

Reputation: 530

I suggest you to look for select

it allow you to check if a file descriptor is ready for read/write/expect operation

Upvotes: 0

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