The terminal mentions that there is an attributeerror 'group' has no attribute 'left'

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Python

import pygame
import sys
import random 
from pygame.locals import*



# Parameter sweep variables
if len(sys.argv) < 4:
    n = 10  # Number of shrimps
    maxVel = 2  # Maximum velocity
    randDeath = 1  # Random chance of death
else:
    n = int(sys.argv[1])
    maxVel = int(sys.argv[2])
    randDeath = int(sys.argv[3])

print("\nPARAMETERS\n")
print("Number of shrimp", n)
print("Maximum velocity", maxVel)
print("Possibility of death", randDeath)
            


        
# General setup
pygame.init()
clock = pygame.time.Clock()

class Shrimp(pygame.sprite.Sprite):
    def __init__(self, picture_path, pos_x, pos_y):
        super().__init__()
        self.image = pygame.image.load(picture_path)
        self.rect = self.image.get_rect()
        self.rect.center = [pos_x, pos_y]
     
#Game Screen
screen_width = 1680
screen_height = 1050
screen = pygame.display.set_mode((screen_width, screen_height))
background = pygame.image.load('background2.png')

#the shrimp 
shrimp_group = pygame.sprite.Group()
for shrimp in range (n) :
    new_shrimp =  Shrimp("shrimp-anemone.png", random.randrange(0, screen_width),random.randrange(0, screen_height))    
    shrimp_group.add(new_shrimp)

direction = 1 

speed_x = 5
speed_y = 4

run = True
 
# Creating an infinite loop
# to run our game
while run:

 
    # Changing the direction and x,y coordinate
    # of the object if the coordinate of left
    # side is less than equal to 20 or right side coordinate
    # is greater than equal to 580
    if shrimp_group.left <= 20 or shrimp_group.right >= 580:
        direction *= -1
        speed_x = random(0, 8) * direction
        speed_y = random(0, 8) * direction
 
        # Changing the value if speed_x
        # and speed_y both are zero
        if speed_x == 0 and speed_y == 0:
            speed_x = random(2, 8) * direction
            speed_y = random(2, 8) * direction
 
    # Changing the direction and x,y coordinate
    # of the object if the coordinate of top
    # side is less than equal to 20 or bottom side coordinate
    # is greater than equal to 580
    if shrimp_group.top <= 20 or shrimp_group.bottom >= 580:
        direction *= -1
        speed_x = random(0, 8) * direction
        speed_y = random(0, 8) * direction
 
        # Changing the value if speed_x
        # and speed_y both are zero
        if speed_x == 0 and speed_y == 0:
            speed_x = random(2, 8) * direction
            speed_y = random(2, 8) * direction
 
    # Adding speed_x and speed_y
    # in left and top coordinates of object
    shrimp_group.left += speed_x
    shrimp_group.top += speed_y
    
    
#prevent the screen from crashing and displaying the screen
while True:
    for event in pygame.event.get():
        if event.type == pygame.QUIT:
            pygame.quit()
            sys.exit()  
   
        
        pygame.display.flip()
        screen.blit(background,(0,0))
        shrimp_group.draw(screen)
        clock.tick(60)

What I have tried:

I want to make my sprites move randomly, but I keep receiving an attribute error not knowing why. And I am unsure of how to fix it. This is my first time working with pygame as it's part of a university project.