Welcome folks today in this blog post we will be building a tetris game in python using pygame library. All the full source code of the application is shown below.

Get Started

In order to get started you need to install the following library using the pip command as shown below

pip install pygame

After installing this library you need to make an app.py file and copy paste the following code

app.py

import pygame
import random

"""
10 x 20 square grid
shapes: S, Z, I, O, J, L, T
represented in order by 0 - 6
"""

pygame.font.init()

# GLOBALS VARS
s_width = 800
s_height = 700
play_width = 300  # meaning 300 // 10 = 30 width per block
play_height = 600  # meaning 600 // 20 = 20 height per blo ck
block_size = 30

top_left_x = (s_width - play_width) // 2
top_left_y = s_height - play_height


# SHAPE FORMATS

S = [['.....',
      '.....',
      '..00.',
      '.00..',
      '.....'],
     ['.....',
      '..0..',
      '..00.',
      '...0.',
      '.....']]

Z = [['.....',
      '.....',
      '.00..',
      '..00.',
      '.....'],
     ['.....',
      '..0..',
      '.00..',
      '.0...',
      '.....']]

I = [['..0..',
      '..0..',
      '..0..',
      '..0..',
      '.....'],
     ['.....',
      '0000.',
      '.....',
      '.....',
      '.....']]

O = [['.....',
      '.....',
      '.00..',
      '.00..',
      '.....']]

J = [['.....',
      '.0...',
      '.000.',
      '.....',
      '.....'],
     ['.....',
      '..00.',
      '..0..',
      '..0..',
      '.....'],
     ['.....',
      '.....',
      '.000.',
      '...0.',
      '.....'],
     ['.....',
      '..0..',
      '..0..',
      '.00..',
      '.....']]

L = [['.....',
      '...0.',
      '.000.',
      '.....',
      '.....'],
     ['.....',
      '..0..',
      '..0..',
      '..00.',
      '.....'],
     ['.....',
      '.....',
      '.000.',
      '.0...',
      '.....'],
     ['.....',
      '.00..',
      '..0..',
      '..0..',
      '.....']]

T = [['.....',
      '..0..',
      '.000.',
      '.....',
      '.....'],
     ['.....',
      '..0..',
      '..00.',
      '..0..',
      '.....'],
     ['.....',
      '.....',
      '.000.',
      '..0..',
      '.....'],
     ['.....',
      '..0..',
      '.00..',
      '..0..',
      '.....']]

shapes = [S, Z, I, O, J, L, T]
shape_colors = [(0, 255, 0), (255, 0, 0), (0, 255, 255), (255, 255, 0), (255, 165, 0), (0, 0, 255), (128, 0, 128)]
# index 0 - 6 represent shape


class Piece(object):
    rows = 20  # y
    columns = 10  # x

    def __init__(self, column, row, shape):
        self.x = column
        self.y = row
        self.shape = shape
        self.color = shape_colors[shapes.index(shape)]
        self.rotation = 0  # number from 0-3


def create_grid(locked_positions={}):
    grid = [[(0,0,0) for x in range(10)] for x in range(20)]

    for i in range(len(grid)):
        for j in range(len(grid[i])):
            if (j,i) in locked_positions:
                c = locked_positions[(j,i)]
                grid[i][j] = c
    return grid


def convert_shape_format(shape):
    positions = []
    format = shape.shape[shape.rotation % len(shape.shape)]

    for i, line in enumerate(format):
        row = list(line)
        for j, column in enumerate(row):
            if column == '0':
                positions.append((shape.x + j, shape.y + i))

    for i, pos in enumerate(positions):
        positions[i] = (pos[0] - 2, pos[1] - 4)

    return positions


def valid_space(shape, grid):
    accepted_positions = [[(j, i) for j in range(10) if grid[i][j] == (0,0,0)] for i in range(20)]
    accepted_positions = [j for sub in accepted_positions for j in sub]
    formatted = convert_shape_format(shape)

    for pos in formatted:
        if pos not in accepted_positions:
            if pos[1] > -1:
                return False

    return True


def check_lost(positions):
    for pos in positions:
        x, y = pos
        if y < 1:
            return True
    return False


def get_shape():
    global shapes, shape_colors

    return Piece(5, 0, random.choice(shapes))


def draw_text_middle(text, size, color, surface):
    font = pygame.font.SysFont('comicsans', size, bold=True)
    label = font.render(text, 1, color)

    surface.blit(label, (top_left_x + play_width/2 - (label.get_width() / 2), top_left_y + play_height/2 - label.get_height()/2))


def draw_grid(surface, row, col):
    sx = top_left_x
    sy = top_left_y
    for i in range(row):
        pygame.draw.line(surface, (128,128,128), (sx, sy+ i*30), (sx + play_width, sy + i * 30))  # horizontal lines
        for j in range(col):
            pygame.draw.line(surface, (128,128,128), (sx + j * 30, sy), (sx + j * 30, sy + play_height))  # vertical lines


def clear_rows(grid, locked):
    # need to see if row is clear the shift every other row above down one

    inc = 0
    for i in range(len(grid)-1,-1,-1):
        row = grid[i]
        if (0, 0, 0) not in row:
            inc += 1
            # add positions to remove from locked
            ind = i
            for j in range(len(row)):
                try:
                    del locked[(j, i)]
                except:
                    continue
    if inc > 0:
        for key in sorted(list(locked), key=lambda x: x[1])[::-1]:
            x, y = key
            if y < ind:
                newKey = (x, y + inc)
                locked[newKey] = locked.pop(key)


def draw_next_shape(shape, surface):
    font = pygame.font.SysFont('comicsans', 30)
    label = font.render('Next Shape', 1, (255,255,255))

    sx = top_left_x + play_width + 50
    sy = top_left_y + play_height/2 - 100
    format = shape.shape[shape.rotation % len(shape.shape)]

    for i, line in enumerate(format):
        row = list(line)
        for j, column in enumerate(row):
            if column == '0':
                pygame.draw.rect(surface, shape.color, (sx + j*30, sy + i*30, 30, 30), 0)

    surface.blit(label, (sx + 10, sy- 30))


def draw_window(surface):
    surface.fill((0,0,0))
    # Tetris Title
    font = pygame.font.SysFont('comicsans', 60)
    label = font.render('TETRIS', 1, (255,255,255))

    surface.blit(label, (top_left_x + play_width / 2 - (label.get_width() / 2), 30))

    for i in range(len(grid)):
        for j in range(len(grid[i])):
            pygame.draw.rect(surface, grid[i][j], (top_left_x + j* 30, top_left_y + i * 30, 30, 30), 0)

    # draw grid and border
    draw_grid(surface, 20, 10)
    pygame.draw.rect(surface, (255, 0, 0), (top_left_x, top_left_y, play_width, play_height), 5)
    # pygame.display.update()


def main():
    global grid

    locked_positions = {}  # (x,y):(255,0,0)
    grid = create_grid(locked_positions)

    change_piece = False
    run = True
    current_piece = get_shape()
    next_piece = get_shape()
    clock = pygame.time.Clock()
    fall_time = 0
    level_time = 0
    fall_speed = 0.27
    score = 0
    
    while run:

        grid = create_grid(locked_positions)
        fall_time += clock.get_rawtime()
        level_time += clock.get_rawtime()
        clock.tick()

        if level_time/1000 > 4:
            level_time = 0
            if fall_speed > 0.15:
                fall_speed -= 0.005
            

        # PIECE FALLING CODE
        if fall_time/1000 >= fall_speed:
            fall_time = 0
            current_piece.y += 1
            if not (valid_space(current_piece, grid)) and current_piece.y > 0:
                current_piece.y -= 1
                change_piece = True

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

            if event.type == pygame.KEYDOWN:
                if event.key == pygame.K_LEFT:
                    current_piece.x -= 1
                    if not valid_space(current_piece, grid):
                        current_piece.x += 1

                elif event.key == pygame.K_RIGHT:
                    current_piece.x += 1
                    if not valid_space(current_piece, grid):
                        current_piece.x -= 1
                elif event.key == pygame.K_UP:
                    # rotate shape
                    current_piece.rotation = current_piece.rotation + 1 % len(current_piece.shape)
                    if not valid_space(current_piece, grid):
                        current_piece.rotation = current_piece.rotation - 1 % len(current_piece.shape)

                if event.key == pygame.K_DOWN:
                    # move shape down
                    current_piece.y += 1
                    if not valid_space(current_piece, grid):
                        current_piece.y -= 1

                '''if event.key == pygame.K_SPACE:
                    while valid_space(current_piece, grid):
                        current_piece.y += 1
                    current_piece.y -= 1
                    print(convert_shape_format(current_piece))'''  # todo fix

        shape_pos = convert_shape_format(current_piece)

        # add piece to the grid for drawing
        for i in range(len(shape_pos)):
            x, y = shape_pos[i]
            if y > -1:
                grid[y][x] = current_piece.color

        # IF PIECE HIT GROUND
        if change_piece:
            for pos in shape_pos:
                p = (pos[0], pos[1])
                locked_positions[p] = current_piece.color
            current_piece = next_piece
            next_piece = get_shape()
            change_piece = False

            # call four times to check for multiple clear rows
            if clear_rows(grid, locked_positions):
                score += 10

        draw_window(win)
        draw_next_shape(next_piece, win)
        pygame.display.update()

        # Check if user lost
        if check_lost(locked_positions):
            run = False

    draw_text_middle("You Lost", 40, (255,255,255), win)
    pygame.display.update()
    pygame.time.delay(2000)


def main_menu():
    run = True
    while run:
        win.fill((0,0,0))
        draw_text_middle('Press any key to begin.', 60, (255, 255, 255), win)
        pygame.display.update()
        for event in pygame.event.get():
            if event.type == pygame.QUIT:
                run = False

            if event.type == pygame.KEYDOWN:
                main()
    pygame.quit()


win = pygame.display.set_mode((s_width, s_height))
pygame.display.set_caption('Tetris')

main_menu()  # start game

And now if you execute the python script by typing the below command

python app.py