I am trying to make a countdown timer that prints the time remaining, and when you input something, it prints what you inputted. My problem is I don't want to wait for the input, just keep running the timer. My incorrect code:
timer = 100
while True:
print(timer)
timer -= 1
if input('> '):
print('the output of input')
You could say I want to have the timer printing the time in the background.
Here's a function that will timeout if no input is given:
import select
import sys
def timeout_input(timeout, prompt="", timeout_value=None):
sys.stdout.write(prompt)
sys.stdout.flush()
ready, _, _ = select.select([sys.stdin], [], [], timeout)
if ready:
return sys.stdin.readline().rstrip('\n')
else:
sys.stdout.write('\n')
sys.stdout.flush()
return timeout_value
You can easily modify it so it shows the remaining time by changing the timeout value on select.select to 1, and looping timeout times.
Standard input and standard output (accessed via input() and print()) are not a good choice for writing interactive asynchronous user interface (UI). Python support a few UIs via it's standard library. For example, curses is a text based user interface available on many POSIX systems. Here is an exmaple code for showing a countdown timer while accepting a number from the user:
import time
import curses
def get_number(seconds):
def _get_number(stdscr):
stdscr.clear()
timeout = time.time() + seconds
s = ""
while time.time() <= timeout:
time_left = int(timeout - time.time())
stdscr.addstr(0, 0, 'Countdown: {} {}'.format(time_left,
"*" * time_left + " " * seconds))
stdscr.addstr(2, 0, ' ' * 50)
stdscr.addstr(2, 0, 'Your Input: {}'.format(s))
stdscr.refresh()
stdscr.timeout(100)
code = stdscr.getch()
stdscr.addstr(10, 0, 'Code: {}'.format(code)) # for debug only
stdscr.refresh()
if ord("0") <= code <= ord("9"):
s += chr(code)
continue
if code == 10 and s: # newline
return int(s)
if code == 127: # backspace
s = s[:-1]
return curses.wrapper(_get_number)
print(get_number(10))
