How to Build a Flappy Bird Clone with Python and Pygame

1. Demo

Previously I played Flappy Bird on my phone, so I wrote a version using Python 3 and the pygame module. The game runs smoothly, includes background music, and surprises you with its fluid animation.

Download the game and install pygame with pip install pygame. Then run the .py file to see the first screen.

Click the "Play" button in the image below to start the game.

The game plays music during play; be sure to download the accompanying assets so the sound works.

2. Full source code

The following code implements the Flappy Bird clone, defining classes for Bird, Pipe, Stone, Bullet, and various helper functions for loading images, handling collisions, scoring, level changes, and a settings menu.

import math
import os
import time
from random import randint, uniform
import pygame
from pygame.locals import *
from collections import deque

FPS = 60
BK_WIDTH = 900  # background width
BK_HEIGHT = 650  # background height
PIPE_WIDTH = 80
PIPE_HEIGHT = 10
PIPE_HEAD_HEIGHT = 32
# ... (additional constants and global variables) ...

class Bullet(pygame.sprite.Sprite):
    speed = BULLET_SPEED
    width = BULLET_WIETH
    height = BULLET_HEIGHT
    def __init__(self, bird, images):
        super(Bullet, self).__init__()
        self.x, self.y = bird.x, bird.y
        self.bullet = images
        self.mask_bullet = pygame.mask.from_surface(self.bullet)
    def update(self):
        self.x = self.x + self.speed * frames_to_msec(1)
    @property
    def image(self):
        return self.bullet
    @property
    def mask(self):
        return self.mask_bullet
    @property
    def rect(self):
        return Rect(self.x, self.y, Bullet.width, Bullet.height)
    def visible(self):
        return 0 < self.x < BK_WIDTH + Bullet.width

class Bird(pygame.sprite.Sprite):
    width = BIRD_WIDTH
    height = BIRD_HEIGHT
    sink_gravity = 0.001
    def __init__(self, x, y, level, images):
        super(Bird, self).__init__()
        self.x, self.y = x, y
        self.wing_up, self.wing_mid, self.wing_down = images
        self.mask_wing_up = pygame.mask.from_surface(self.wing_up)
        self.mask_wing_mid = pygame.mask.from_surface(self.wing_mid)
        self.mask_wing_down = pygame.mask.from_surface(self.wing_down)
        self.inital_speed = 0
        self.level = level
        self.score = 0
    def update(self, t):
        y_ = self.inital_speed * t + 0.5 * self.sink_gravity * t * t
        if self.inital_speed <= 0.3:
            self.inital_speed += self.sink_gravity * t
        self.y += y_
    @property
    def image(self):
        if pygame.time.get_ticks() % 400 >= 120:
            return self.wing_up
        elif pygame.time.get_ticks() % 400 >= 280:
            return self.wing_mid
        else:
            return self.wing_down
    @property
    def mask(self):
        if pygame.time.get_ticks() % 400 >= 120:
            return self.mask_wing_up
        elif pygame.time.get_ticks() % 400 >= 280:
            return self.mask_wing_mid
        else:
            return self.mask_wing_down
    @property
    def rect(self):
        return Rect(self.x, self.y, Bird.width, Bird.height)

# Additional classes: Pipe, Stone, utility functions (load_image, load_images, frames_to_msec, msec_to_frames, game_loop, setting, buttons, main, etc.)

if __name__ == "__main__":
    main()