Why is my display not responding while waiting for input?

Solution 1:

You cannot use input in the application loop. input waits for an input. While the system is waiting for input, the application loop will halt and the game will not respond.

Use the KEYDOWN event instead of input:

run = True
while run:
    event_list = pygame.event.get()
    for event in event_list:
        if event.type == pygame.QUIT:
            run = False

        if event.type == pygame.KEYDOWN:
            if pygame.key == pygame.K_1:
                # [...]
            if pygame.key == pygame.K_2:
                # [...]

Another option is to get the input in a separate thread.

Minimal example:

import pygame
import threading

pygame.init()
window = pygame.display.set_mode((400, 400))
clock = pygame.time.Clock()

color = "red"
def get_input():
    global color
    color = input('enter color (e.g. blue): ')

input_thread = threading.Thread(target=get_input)
input_thread.start()

run = True
while run:
    clock.tick(60)
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            run = False          

    window_center = window.get_rect().center
    window.fill(0)
    pygame.draw.circle(window, color, window_center, 100)
    pygame.display.flip()

pygame.quit()
exit()