I am making a Calculator with Pygame and I want to check if the user has pressed a key which is an integer. If the key is an integer like 1 or 2 then blit the number onto the screen.
I have tried but many times but failed

Here's my code

```
import pygame, math

pygame.init()
screen_width = 1200
screen_height = 500
gameWindow = pygame.display.set_mode((screen_width, screen_height))
pygame.display.set_caption('Calculator')
red = (255, 0, 0)
green = (0, 255, 0)
blue = (0, 0, 255)
white = (255, 255, 255)
black = (0, 0, 0)
grey = (128, 128, 128)
font = pygame.font.SysFont('comicsans', 40)
fps = 60
clock = pygame.time.Clock()

def text_screen(text, color, x, y):
     screen_text = font.render(text, True, color)
     gameWindow.blit(screen_text, [x ,y])

def welcome_screen(run):
    clock.tick(fps) 
    gameWindow.fill(grey)
    while not run:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                 run = True
            if event.type == pygame.KEYDOWN:
                if event.key == # Code to check whether the key is integer or not:
                     pass
        pygame.display.update()

def gameLoop(run):
    clock.tick(fps)
    gameWindow.fill(grey)
    while not run:
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run = True
        pygame.display.update()

if __name__ == "__main__":
    welcome_screen(False)

```