tkinter-moves-collisions.py

#!/usr/bin/env python3
# Requires Python 3.6+

import tkinter as tk
from random import randint

w, h = 800, 600
s = 80              # size of disk
root = tk.Tk()
canvas = tk.Canvas(root, width=w, height=h, bg="black")
canvas.pack()

player = canvas.create_oval(0, 0, s, s, fill='white')
canvas.move(player, w // 2 -15, h // 2 -15)

arrows = {"Up":(0,-5), "Down":(0,5), "Left":(-5,0), "Right":(5,0)}
for key in arrows:
    moves = lambda _, key=key: canvas.move(player, *arrows[key])
    canvas.bind_all(f'<KeyPress-{key}>', moves)

def collisions():
    px, py = canvas.bbox(player)[0:2]
    if not 0 <= px + 1 <= w - s or not 0 <= py + 1 <= h - s:
        canvas.itemconfig(player, fill='red')
        return False
    for enemy in enemies:
        canvas.move(enemy, randint(-1, 1), randint(-1, 1))
        ex, ey = canvas.bbox(enemy)[0:2]
        dist = ((px - ex) ** 2 + (py - ey) ** 2) ** 0.5
        if dist < s:
            canvas.itemconfig(enemy, fill='red')
            return False
    return True

def spawn():
    if randint(0, 5) == 0:
        px, py = canvas.bbox(player)[0:2]
        enemy = canvas.create_oval(-s, -s, 0, 0, fill="green")
        ex, ey = randint(0, w - s), randint(0, h - s)
        dist = ((px - ex) ** 2 + (py - ey) ** 2) ** 0.5
        if dist > s * 1.1:
            canvas.move(enemy, ex + 1 + s, ey + 1 + s)
            enemies.append(enemy)
        else:
            del enemy
    if collisions():
        root.after(50, spawn)

enemies = []
spawn()
root.mainloop()