Build a Plants vs Zombies Clone in Python with Pygame – Step‑by‑Step Tutorial

Hello, I’m 面师兄. Today I recommend a Python practice project: building a Plants vs Zombies clone using Pygame.

1. Import required modules

import pygame
import random

2. Configure image path

IMAGE_PATH = 'imgs/'

3. Set screen dimensions

scrrr_width = 800
scrrr_height = 560

4. Game‑over flag

GAMEOVER = False

5. Image loading error handling

LOG = 'File:{} method:{} error'.format(__file__, __name__)

6. Map class

class Map():
    pass

7. Store map image names

map_names_list = [IMAGE_PATH + 'map1.png', IMAGE_PATH + 'map2.png']

8. Initialize map

def __init__(self, x, y, img_index):
    self.image = pygame.image.load(Map.map_names_list[img_index])
    self.position = (x, y)

9. Plantability flag

self.can_grow = True

10. Load map onto screen

def load_map(self):
    MainGame.window.blit(self.image, self.position)

11. Plant base class

class Plant(pygame.sprite.Sprite):
    def __init__(self):
        super(Plant, self).__init__()
        self.live = True

12. Load plant image

def load_image(self):
    if hasattr(self, 'image') and hasattr(self, 'rect'):
        MainGame.window.blit(self.image, self.rect)
    else:
        print(LOG)

13. Sunflower class

class Sunflower(Plant):
    def __init__(self, x, y):
        super(Sunflower, self).__init__()
        self.image = pygame.image.load('imgs/sunflower.png')
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y
        self.price = 50
        self.hp = 100
        self.time_count = 0

14. Sunflower generates money

def produce_money(self):
    self.time_count += 1
    if self.time_count == 25:
        MainGame.money += 5
        self.time_count = 0

15. Display sunflower

def display_sunflower(self):
    MainGame.window.blit(self.image, self.rect)

16. PeaShooter class

class PeaShooter(Plant):
    def __init__(self, x, y):
        super(PeaShooter, self).__init__()
        self.image = pygame.image.load('imgs/peashooter.png')
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y
        self.price = 50
        self.hp = 200
        self.shot_count = 0

17. Shooting method

def shot(self):
    should_fire = False
    for zombie in MainGame.zombie_list:
        if zombie.rect.y == self.rect.y and zombie.rect.x < 800 and zombie.rect.x > self.rect.x:
            should_fire = True
    if self.live and should_fire:
        self.shot_count += 1
        if self.shot_count == 25:
            peabullet = PeaBullet(self)
            MainGame.peabullet_list.append(peabullet)
            self.shot_count = 0

18. Display PeaShooter

def display_peashooter(self):
    MainGame.window.blit(self.image, self.rect)

19. PeaBullet class

class PeaBullet(pygame.sprite.Sprite):
    def __init__(self, peashooter):
        self.live = True
        self.image = pygame.image.load('imgs/peabullet.png')
        self.damage = 50
        self.speed = 10
        self.rect = self.image.get_rect()
        self.rect.x = peashooter.rect.x + 60
        self.rect.y = peashooter.rect.y + 15
    def move_bullet(self):
        if self.rect.x < scrrr_width:
            self.rect.x += self.speed
        else:
            self.live = False
    def hit_zombie(self):
        for zombie in MainGame.zombie_list:
            if pygame.sprite.collide_rect(self, zombie):
                self.live = False
                zombie.hp -= self.damage
                if zombie.hp <= 0:
                    zombie.live = False
                self.nextLevel()
    def nextLevel(self):
        MainGame.score += 20
        MainGame.remnant_score -= 20
        for i in range(1, 100):
            if MainGame.score == 100 * i and MainGame.remnant_score == 0:
                MainGame.remnant_score = 100 * i
                MainGame.shaoguan += 1
                MainGame.produce_zombie += 50
    def display_peabullet(self):
        MainGame.window.blit(self.image, self.rect)

20. Zombie class

class Zombie(pygame.sprite.Sprite):
    def __init__(self, x, y):
        super(Zombie, self).__init__()
        self.image = pygame.image.load('imgs/zombie.png')
        self.rect = self.image.get_rect()
        self.rect.x = x
        self.rect.y = y
        self.hp = 1000
        self.damage = 2
        self.speed = 1
        self.live = True
        self.stop = False
    def move_zombie(self):
        if self.live and not self.stop:
            self.rect.x -= self.speed
        if self.rect.x < -80:
            MainGame().gameOver()
    def hit_plant(self):
        for plant in MainGame.plants_list:
            if pygame.sprite.collide_rect(self, plant):
                self.stop = True
                self.eat_plant(plant)
    def eat_plant(self, plant):
        plant.hp -= self.damage
        if plant.hp <= 0:
            a = plant.rect.y // 80 - 1
            b = plant.rect.x // 80
            map = MainGame.map_list[a][b]
            map.can_grow = True
            plant.live = False
            self.stop = False
    def display_zombie(self):
        MainGame.window.blit(self.image, self.rect)

21. Main game class

class MainGame():
    shaoguan = 1
    score = 0
    remnant_score = 100
    money = 200
    map_points_list = []
    map_list = []
    plants_list = []
    peabullet_list = []
    zombie_list = []
    count_zombie = 0
    produce_zombie = 100
    def init_window(self):
        pygame.display.init()
        MainGame.window = pygame.display.set_mode([scrrr_width, scrrr_height])
    def draw_text(self, content, size, color):
        pygame.font.init()
        font = pygame.font.SysFont('kaiti', size)
        return font.render(content, True, color)
    def load_help_text(self):
        text1 = self.draw_text('1.左键创建向日葵 2.右键创建豌豆射手', 26, (255,0,0))
        MainGame.window.blit(text1, (5,5))
    def init_plant_points(self):
        for y in range(1,7):
            points = []
            for x in range(10):
                points.append((x,y))
            MainGame.map_points_list.append(points)
    def init_map(self):
        for points in MainGame.map_points_list:
            temp_map_list = []
            for point in points:
                if (point[0] + point[1]) % 2 == 0:
                    map = Map(point[0]*80, point[1]*80, 0)
                else:
                    map = Map(point[0]*80, point[1]*80, 1)
                temp_map_list.append(map)
            MainGame.map_list.append(temp_map_list)
    def load_map(self):
        for temp_map_list in MainGame.map_list:
            for map in temp_map_list:
                map.load_map()
    def load_plants(self):
        for plant in MainGame.plants_list:
            if plant.live:
                if isinstance(plant, Sunflower):
                    plant.display_sunflower()
                    plant.produce_money()
                elif isinstance(plant, PeaShooter):
                    plant.display_peashooter()
                    plant.shot()
                else:
                    MainGame.plants_list.remove(plant)
    def load_peabullets(self):
        for b in MainGame.peabullet_list:
            if b.live:
                b.display_peabullet()
                b.move_bullet()
                b.hit_zombie()
            else:
                MainGame.peabullet_list.remove(b)
    def deal_events(self):
        for e in pygame.event.get():
            if e.type == pygame.QUIT:
                self.gameOver()
            elif e.type == pygame.MOUSEBUTTONDOWN:
                x = e.pos[0] // 80
                y = e.pos[1] // 80
                map = MainGame.map_list[y-1][x]
                if e.button == 1:
                    if map.can_grow and MainGame.money >= 50:
                        sunflower = Sunflower(map.position[0], map.position[1])
                        MainGame.plants_list.append(sunflower)
                        map.can_grow = False
                        MainGame.money -= 50
                elif e.button == 3:
                    if map.can_grow and MainGame.money >= 50:
                        peashooter = PeaShooter(map.position[0], map.position[1])
                        MainGame.plants_list.append(peashooter)
                        map.can_grow = False
                        MainGame.money -= 50
    def init_zombies(self):
        for i in range(1,7):
            dis = random.randint(1,5) * 200
            zombie = Zombie(800 + dis, i*80)
            MainGame.zombie_list.append(zombie)
    def load_zombies(self):
        for zombie in MainGame.zombie_list:
            if zombie.live:
                zombie.display_zombie()
                zombie.move_zombie()
                zombie.hit_plant()
            else:
                MainGame.zombie_list.remove(zombie)
    def start_game(self):
        self.init_window()
        self.init_plant_points()
        self.init_map()
        self.init_zombies()
        while not GAMEOVER:
            MainGame.window.fill((255,255,255))
            MainGame.window.blit(self.draw_text('当前钱数$: {}'.format(MainGame.money), 26, (255,0,0)), (500,40))
            MainGame.window.blit(self.draw_text('当前关数{}，得分{},距离下关还差{}分'.format(MainGame.shaoguan, MainGame.score, MainGame.remnant_score), 26, (255,0,0)), (5,40))
            self.load_help_text()
            self.load_map()
            self.load_plants()
            self.load_peabullets()
            self.deal_events()
            self.load_zombies()
            MainGame.count_zombie += 1
            if MainGame.count_zombie == MainGame.produce_zombie:
                self.init_zombies()
                MainGame.count_zombie = 0
            pygame.time.wait(10)
            pygame.display.update()
    def gameOver(self):
        MainGame.window.blit(self.draw_text('游戏结束', 50, (255,0,0)), (300,200))
        pygame.time.wait(400)
        global GAMEOVER
        GAMEOVER = True
if __name__ == '__main__':
    game = MainGame()
    game.start_game()

Resulting screenshot of the finished game: