In python3 compiled code, always does not, please help see what reason be? Thank you,

The import sys
The import pygame

Def run_game () :
Pygame. The init ()
Screen=pygame. Display. Set_mode ((1200800))
Pygame. Display. Set_caption (" Alien Invasion1 ")

While True:
For the event in pygame. Event. The get () :
If the event. The type==pygame. QUIT:
Sys. The exit ()

Pygame. Display. Flip ()

Run_game ()