How to camera scroll Python Pygame

Question

I have this camera class im working on and attempting to make the camera follow the player and scroll the background. ive watched dozens of youtube videos and read similar questions on SO but im stuck heres the source code: (main.py)

import pygame
import player
import enemy
import environment
import collision as collision
import camera

pygame.init()

size = WIDTH, HEIGHT = (640, 480)
screen = pygame.display.set_mode(size)

pygame.display.set_caption("Game 2")

FPS = 60
fpsclock = pygame.time.Clock()

player.player1 = player.player(300, 410, 32, 32)
player.player1.initialize()

enemyVector = []
enemy.enemy1 = enemy.enemy(160, 170, 32, 32)
enemy.enemy1.initialize()
enemyVector.append(enemy.enemy1)

environmentVector = []
#environment.environment1.load_map(environmentVector)




counter1 = 0
counter2 = 0
string = ''
with open('map.txt', 'r') as f:
    for line in f:
        for character in line:
            if character == '0':
                pass
            elif character == '1':
                environment.environment1 = environment.environment(160, 100, 32, 32)
                environmentVector.append(environment.environment1)
                environmentVector[-1].x = counter1 * 32
                environmentVector[-1].y = counter2 * 32
            counter1 += 1
        counter1 = 0
        counter2 += 1

print(environmentVector[1].x)

run = True
while run:
    pygame.time.delay(50)

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

keys = pygame.key.get_pressed()

if player.player1.active:
    player.player1.frame += 1
if player.player1.frame >= 2:
    player.player1.frame = 0

for i in enemyVector:
    if i.ready_to_move():
        i.move()
    if i.ready_to_animate():
        i.animate()

player.player1.playerImage = player.player1.cells[player.player1.frame + player.player1.animation]



for i in enemyVector:
    i.enemyImage = i.cells[i.frame + i.animation]

if keys[pygame.K_LEFT] and player.player1.canMoveLeft and player.player1.x > player.player1.vel:
    player.player1.x -= player.player1.vel
    player.player1.animation = 3
    player.player1.active = True
elif keys[pygame.K_RIGHT] and player.player1.canMoveRight and player.player1.x < 640 - player.player1.width - player.player1.vel:
    player.player1.x += player.player1.vel
    player.player1.animation = 6
    player.player1.active = True
elif keys[pygame.K_UP] and player.player1.canMoveUp and player.player1.y > player.player1.vel:
    player.player1.y -= player.player1.vel
    player.player1.animation = 9
    player.player1.active = True
elif keys[pygame.K_DOWN] and player.player1.canMoveDown and player.player1.y < 480 - player.player1.height - player.player1.vel:
    player.player1.y += player.player1.vel
    player.player1.animation = 0
    player.player1.active = True
elif keys[pygame.K_s]:
    player.player1.attack = True
    player.player1.animation = 12
else:
    player.player1.active = False


collision.check_collision_enemy(enemyVector, environmentVector)
collision.check_collision_player(player.player1, environmentVector)



player.player1.update_xy()

enemy.enemy1.update_xy()

for i in environmentVector:
    i.update_xy()


screen.fill((0, 0, 0))

for i in enemyVector:
    screen.blit(i.enemyImage, (i.x, i.y))

screen.blit(player.player1.playerImage, (player.player1.x, player.player1.y))


for i in environmentVector:
    pygame.draw.rect(screen, (255,255,255), (i.x, i.y, 32, 32))

pygame.display.flip()
fpsclock.tick(FPS)

pygame.quit()

(camera.py):

class Camera:
    def __init__(self, players):
        self.left_viewbox = display_width/2 - display_width/8
        self.right_viewbox = display_width/2 + display_width/10

    def follow(self, shift_x):
        virtualwindow.x += shift_x
        print virtualwindow.x
        for i in players:   
            i.rect.x += shift_x

    def viewbox(self):
        if player.x <= self.left_viewbox:
            view_difference = self.left_viewbox - player.x
            player.x = self.left_viewbox
            self.follow(view_difference)

        if player.x >= self.right_viewbox:
            view_difference = self.right_viewbox - player.x
            player.x = self.right_viewbox
            self.follow(view_difference)

how could this camera class be amended and implemented so that the camera follows the player and scrolls a list of recs in the background