Tetris implemented in python

tetris.py

#!/usr/bin/env python2

import Tkinter
import random
import sys

# Represents one block in tetris
class TetrisBlock():

    SHAPES = [[(0,0), (1,0), (0,1), (1,1)], # BOX
              [(0,0), (1,0), (2,0), (3,0)], # LINE
              [(2,0), (0,1), (1,1), (2,1)], # Right L
              [(0,0), (0,1), (1,1), (2,1)], # Left L
              [(0,1), (1,1), (1,0), (2,0)], # Right S
              [(0,0), (1,0), (1,1), (2,1)], # Left S
              [(1,0), (0,1), (1,1), (2,1)]] # Pyramide

    COLORS = ["yellow","lightblue","orange","blue","green","red","purple"]

    def __init__(self, tetris, i=None):
        if i is None: i = random.randint(0,6)
        self.shape = self.SHAPES[i]
        self.color = self.COLORS[i]
        self.tetris = tetris
        self.canvas = self.tetris.canvas
        self.boxes = []

        mid = self.tetris.p_width / 2 - self.tetris.ppb / 2

        for point in self.shape:
            x,y = point
            box = self.canvas.create_rectangle(x * self.tetris.ppb + mid,
                                               y * self.tetris.ppb,
                                               (x+1) * self.tetris.ppb + mid,
                                               (y+1) * self.tetris.ppb,
                                               fill = self.color)
            self.boxes += [box]

    def move_box(self, box, x, y):
        x *= self.tetris.ppb
        y *= self.tetris.ppb
        coords = self.canvas.coords(box)

        if coords[3] + y > self.tetris.p_height: return False
        if coords[0] + x < 0: return False
        if coords[2] + x > self.tetris.p_width: return False

        o = set(self.canvas.find_overlapping((coords[0] + coords[2]) / 2 + x,
                                             (coords[1] + coords[3]) / 2 + y,
                                             (coords[0] + coords[2]) / 2 + x,
                                             (coords[1] + coords[3]) / 2 + y ))

        other = set(self.canvas.find_all()) - set(self.boxes)
        if o & other: return False

        return True

    def move_shape(self, x, y):
        for box in self.boxes:
            if not self.move_box(box, x,y): return False
        return True

    def fall(self):
        if self.move_shape(0,1):
            for box in self.boxes:
                self.canvas.move(box,0,self.tetris.ppb)
            return True
        return False

    def move(self, x, y):
        if not self.move_shape(x, y): return False
        else:
            for box in self.boxes:
                self.canvas.move(box, x * self.tetris.ppb, y * self.tetris.ppb)
            return True

    def rotate(self):
        copy = self.boxes[:]
        pivot = copy.pop(2)

        def check(box):
            bc = self.canvas.coords(box)
            pc = self.canvas.coords(pivot)
            xd = bc[0] - pc[0]
            yd = bc[1] - pc[1]
            xm = (-xd-yd) / self.tetris.ppb
            ym = (xd-yd) / self.tetris.ppb
            return xm, ym

        # Check if all blocks can be rotated
        for box in copy:
            x,y = check(box)
            if not self.move_box(box,x,y):
                return False

        # Move blocks
        for box in copy:
            x,y = check(box)
            self.canvas.move(box, x * self.tetris.ppb, y * self.tetris.ppb)

        return True


# Tetris game
class Tetris():

    def __init__(self, width, height, ppb=30):
        self.width = width
        self.height = height
        self.ppb = ppb

        # Calculate pixel dimensions
        self.p_width = self.width * self.ppb
        self.p_height = self.height * self.ppb

        # Game variables
        self.boxes = []
        self.c_box = None
        self.speed = 300

    # Show the UI
    def show(self):
        self.ui = Tkinter.Tk()
        self.ui.title("PyTetris")

        self.canvas = Tkinter.Canvas(self.ui, width=self.p_width,
                                              height=self.p_height)

        self.canvas.pack()

        self.ui.bind("<Key>", self.key_press)
        self.game_frame()

        # Enter Tkinter mainloop
        self.ui.mainloop()

    # Render one game frame
    def game_frame(self):
        if self.c_box is None:
            self.c_box = TetrisBlock(self)

        if not self.c_box.fall():
            # Remove completed lines # TODO
            self.c_box = TetrisBlock(self)

            # Check gameover
            for box in self.c_box.boxes:
                if not self.c_box.move_box(box, 0, 1):
                    print "Game over!"
                    sys.exit()

        self.ui.after(self.speed, self.game_frame)

    # Handle keypresses
    def key_press(self, e):
        if self.c_box is None: return
        if e.keysym == "Left": self.c_box.move(-1,0)
        if e.keysym == "Right": self.c_box.move(1,0)
        if e.keysym == "Down": self.c_box.move(0,1)
        if e.keysym == "Up": self.c_box.rotate()

if __name__ == "__main__":
    t = Tetris(10,20)
    t.show()