How to Get Non-Blocking Console Input in Python?

Getting Non-Blocking Console Input

When creating interactive applications, it's often necessary to accept user input without interrupting ongoing processes. This arises in situations like IRC client development, where a loop continuously receives and interprets server responses.

Problem Statement

In Python, using raw_input for console input halts the loop until the user provides input. To achieve non-blocking input, we require an alternative approach.

Solutions

For Windows users solely working with console input, the msvcrt module is available:

import msvcrt

num = 0
done = False
while not done:
    print(num)
    num += 1

    if msvcrt.kbhit():
        print("you pressed", msvcrt.getch(), "so now I will quit")
        done = True

For Linux environments, the termios module offers a solution:

import sys
import select
import tty
import termios

def isData():
    return select.select([sys.stdin], [], [], 0) == ([sys.stdin], [], [])

old_settings = termios.tcgetattr(sys.stdin)
try:
    tty.setcbreak(sys.stdin.fileno())

    i = 0
    while 1:
        print(i)
        i += 1

        if isData():
            c = sys.stdin.read(1)
            if c == '\x1b':         # x1b is ESC
                break

finally:
    termios.tcsetattr(sys.stdin, termios.TCSADRAIN, old_settings)

For跨 platforms or when including GUI in your application, Pygame is a versatile option:

import pygame
from pygame.locals import *

def display(str):
    text = font.render(str, True, (255, 255, 255), (159, 182, 205))
    textRect = text.get_rect()
    textRect.centerx = screen.get_rect().centerx
    textRect.centery = screen.get_rect().centery

    screen.blit(text, textRect)
    pygame.display.update()

pygame.init()
screen = pygame.display.set_mode( (640,480) )
pygame.display.set_caption('Python numbers')
screen.fill((159, 182, 205))

font = pygame.font.Font(None, 17)

num = 0
done = False
while not done:
    display( str(num) )
    num += 1

    pygame.event.pump()
    keys = pygame.key.get_pressed()
    if keys[K_ESCAPE]:
        done = True

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