Python,Pygame, local variable referenced before assignment - python-3.x

Question

Relatively new to Pygame. I'm trying to make a rectangle move from a character (xeon) like a bullet, horizontally when pressing the downarrow key. I keep getting this error.
"UnboundLocalError: local variable 'bullets' referenced before assignment"
Any feedback is much appreciated. Excuse the mess...........................
import pygame
import time
import random
import sys
import os
pygame.init()
display_width=800
display_height=600
black=(0,0,0)
white=(255,255,255)
red=(200,0,0)
green=(0,200,0)
blue=(0,0,200)
bright_green=(0,255,0)
bright_red=(255,0,0)
gameDisplay=pygame.display.set_mode((800,600))
pygame.display.set_caption("Xeongame")
clock=pygame.time.Clock()
zheImg=pygame.image.load("xeon.png").convert()
bgImg=pygame.image.load("Spacebackground.jpg").convert()
xeon_width=300
def xeon(x,y):
gameDisplay.blit(zheImg,(x,y))
def bullets(x,y,bx,by,bw,bh,color):
while True:
pygame.draw.rect(gameDisplay,color,[bx,by,bw,bh])
def quitgame():
pygame.quit()
quit()
def text_objects(text,font):
textSurface=font.render(text,True,black)
return textSurface,textSurface.get_rect()
def obstacles(obstaclex,obstacley,obstaclew,obstacleh,color):
pygame.draw.rect(gameDisplay,color,[obstaclex,obstacley,obstaclew,obstacleh])
def message_display(text):
largeText=pygame.font.Font("freesansbold.ttf",115)
TextSurf,TextRect=text_objects(text,largeText)
TextRect.center=((display_width/2),(display_height/2))
gameDisplay.blit(TextSurf,TextRect)
pygame.display.update()
time.sleep(1)
game_loop()
def button(msg,x,y,w,h,ic,ac,action=None):
mouse=pygame.mouse.get_pos()
click=pygame.mouse.get_pressed()
if x+w>mouse[0]>x and y+h>mouse[1]>y:
pygame.draw.rect(gameDisplay,ac,(x,y,w,h))
if click[0]==1 and action !=None:
action()
if action=="Play":
game_loop()
elif action=="Quit":
pygame.quit()
quit()
else:
pygame.draw.rect(gameDisplay,ic,(x,y,w,h))
smallText=pygame.font.Font("freesansbold.ttf",20)
textSurf,textRect=text_objects(msg,smallText)
textRect.center=( (x+(w/2)),(y+(h/2)) )
gameDisplay.blit(textSurf,textRect)
largeText=pygame.font.Font("freesansbold.ttf",115)
def game_intro():
intro=True
while intro:
for event in pygame.event.get():
if event.type==pygame.QUIT:
pygame.quit()
quit()
gameDisplay.fill(white)
largeText=pygame.font.Font("freesansbold.ttf",115)
TextSurf,TextRect=text_objects("Xeon",largeText)
TextRect.center=((display_width/2),(display_height/2))
gameDisplay.blit(TextSurf,TextRect)
xeon(10,100)
button("Play",150,450,100,50,green,bright_green,game_loop)
button("Quit",550,450,100,50,red,bright_red,quitgame)
pygame.display.update()
clock.tick(15)
def game_loop():
x=(display_width*.10)
y=(display_height*0.50)
x_change=0
y_change=0
x+=x_change
y+=y_change
##ALTERNATIVE JUMPING
#xeon_gravity=0.8
#xeon_acc=0.5
obstacle_speed=7
obstacle_height=100
obstacle_width=50
obstacle_startx=random.randrange(300,display_width)
obstacle_starty=-100
##bullets
bullets_height=10
bullets_width=50
bullets_startx=xeon_width
bullets_starty=xeon_width
bullets_speed=0.7
bullets_x_change=0
####KEYS
gameExit=False
while not gameExit:
for event in pygame.event.get():
if event.type==pygame.QUIT:
pygame.quit()
quit()
if event.type==pygame.KEYDOWN:
if event.key==pygame.K_RIGHT:
x_change=-5
if event.key==pygame.K_LEFT:
x_change=+5
if event.key==pygame.K_UP:
y_change=-5
if event.key==pygame.K_DOWN:
bullets=True
pygame.draw.rect(gameDisplay,[bx,by,bw,bh,color])
bullets_x_change=-5
if event.type==pygame.KEYUP:
if event.key==pygame.K_LEFT or event.key==pygame.K_RIGHT:
x_change=0
x+=x_change
y+=y_change
rel_x=x%bgImg.get_rect().width
gameDisplay.blit(bgImg,(rel_x-bgImg.get_rect().width,0))
gameDisplay.blit(bgImg,(rel_x,0))
xeon(x_change,y)
bullets(bullets_startx,bullets_starty,bullets_width,bullets_height,blue)
bullets_starty+=bullets_speed
obstacles(obstacle_startx,obstacle_starty,obstacle_width,obstacle_height,red)
obstacle_starty+=obstacle_speed
if obstacle_starty>display_height:
obstacle_starty=0-obstacle_height
obstacle_startx=random.randrange(300,display_width)
pygame.display.update()
clock.tick(60)
game_intro()
game_loop()
pygame.quit()
quit()

Answer 1

The problem is that you have a local variable named bullets (in the game_loop function) and a global function with the same name. When you call the function bullets() in game_loop, Python thinks you mean the local variable to which you haven't assigned anything yet, so the UnboundLocalError is raised.
Rename the function or the variable to avoid the UnboundLocalError.
Here's an answer with more information.
You're also not passing enough arguments to the bullets function.