bind_all_once_in_canvas.py

from tkinter import *
import time


class Rectangle:
    objects = []

    @classmethod
    def all_move_right(cls, event):
        for obj in cls.objects:
            obj.move_right(event)

    @classmethod
    def all_move_left(cls, event):
        for obj in cls.objects:
            obj.move_left(event)

    def __new__(cls, *args, **kwargs):
        instance = object.__new__(cls)
        cls.objects.append(instance)
        return instance

    def __init__(self, canvas, y=100, color='yellow'):
        self.canvas = canvas
        self.y = y
        self.color = color
        self.x = 0
        self.id = canvas.create_rectangle(230, self.y, 270, self.y + 20, fill=self.color)

    def move_right(self, event):
        self.x += 5

    def move_left(self, event):
        self.x -= 5

    def move_action(self):
        position = self.canvas.coords(self.id)
        if position[0] > 360 and self.x > 0:
            self.x = 0
        elif position[0] < 100 and self.x < 0:
            self.x = 0
        self.canvas.move(self.id, self.x, 0)


root = Tk()
canvas1 = Canvas(root, width=500, height=300)
canvas1.pack()
rec1 = Rectangle(canvas=canvas1, y=100, color='blue')
rec2 = Rectangle(canvas=canvas1, y=200, color='green')

# bind event here only on canvas once

def on_keypress_right(event):
    Rectangle.all_move_right(event)

def on_keypress_left(event):
    Rectangle.all_move_left(event)

canvas1.bind_all('<KeyPress-Right>', on_keypress_right)
canvas1.bind_all('<KeyPress-Left>', on_keypress_left)

while True:
    rec1.move_action()
    rec2.move_action()
    root.update()
    time.sleep(0.1)


root.mainloop()