Scrolling game very slow

Question

I am trying to make a scrolling game in Tkinter. However, with all my for loops and functions it is extremely slow.

I am reading the tutorial from Khan Academy's advanced JS. In their JS game everything is fine, so is it just a problem of python is slow or am I doing things inefficiently.

import tkinter as tk
import random
import time
win = tk.Tk()
win.title("Beaver Game")
win.wm_attributes("-topmost", 1)#Makes it stay on top of other windows
canvas = tk.Canvas(win, width=300, height=300, bg='#97FEFF', bd = 0, highlightthickness = 0)   
canvas.pack()
canvas.create_rectangle(0, 270,300, 300, fill = "brown")
win.update()

class Beaver:
    def __init__(self, canvas, color):
        self.canvas = canvas
        self.id = self.canvas.create_rectangle(150,150, 100, 100, fill = color)
        self.y = 0
        self.canvas_height = self.canvas.winfo_height()
        self.canvas_width = self.canvas.winfo_width()
        self.canvas.bind_all('<KeyPress-Up>', self.turn_left)
        self.canvas.bind_all('<KeyPress-Down>', self.turn_right)
        self.sticks = 0
    def draw(self):
        self.canvas.move(self.id, 0, self.y)
        pos = self.canvas.coords(self.id)
        if pos[1] <= 0:
            self.y = 0
        if pos[3] >= self.canvas_height:
            self.y = 0
    def turn_left(self, evt):
        self.y = -3
    def turn_right(self,evt):
        self.y = 3
class Stick:
    def __init__(self, canvas, color, x, y):
        self.canvas = canvas
        self.color = color
        self.x = x
        self.y = y        
    def draw(self):
        canvas.create_rectangle(self.x, self.y, 5, 40, fill = self.color)
beaver = Beaver(canvas, "pink")

grassXs = []
for i in range(25):
     grassXs.append(i * 25)

sticks = []
for i in range(40): 
    sticks.append(Stick(canvas, "black", i * 4 + 100, random.randint(20, 26)))

while 1:
   for i in range(len(grassXs)):
      canvas.create_rectangle(grassXs[i], 250, 270, 270, fill = "green")
      grassXs[i] -= 1
      if (grassXs[i] <= -20):
         grassXs[i] = canvas.winfo_width()
   for i in range(len(sticks)):
       sticks[i].draw()
       sticks[i].x -= 1
   beaver.draw()
   win.update_idletasks()
   win.update()

Answer 1

You are doing animation wrong. As a rule of thumb you shouldn't have your own infinite loop in a Tkinter program. Tkinter already has an efficient infinite loop — the mainloop function.

Here are a few Stack Overflow questions dealing with Tkinter animation:

• simple animation using tkinter
• Moving balls in Tkinter Canvas
• Python Tkinter wireworld animation slowing down over time

I will say that the canvas has performance issues when there are hundreds of thousands of objects on the canvas, and it may start appearing when there are tens of thousands.

In your case, by my estimation you're creating a couple thousand canvas objects per second, and that's just way too many to expect good performance. Considering you're making a side-scroller, you simply don't need to create all those objects every second.