Python - Tkinter 重复 function 不工作？

Question

I am trying to make a function that makes a circle in a random place, in return the first time it executes correctly but after that every time i try to execute it it doesn't work. Please help me and here's the code:

size = 200

class Spots():
    def __init__(self):
        self.avaible = True
    def taken(self):
        self.avaible = False

a1 = Spots()
a2 = Spots()
a3 = Spots()
b1 = Spots()
b2 = Spots()
b3 = Spots()
c1 = Spots()
c2 = Spots()
c3 = Spots()

spots = (a1,a2,a3,b1,b2,b3,c1,c2,c3)

import random as r
from tkinter import *
tk = Tk()
cv = Canvas(tk, width = 200 + size * 3, height = 200 + size * 3)
cv.pack()

def tkO():
    rch = r.choice(spots)
    x = 100
    y = 100
    
    while a1.avaible == True or a2.avaible == True or a3.avaible == True or b1.avaible == True or b2.avaible == True or b3.avaible == True or c1.avaible == True or c2.avaible == True or c3.avaible == True:
        while rch.avaible == False:
            rch = r.choice(spots)
        break
    rch.taken
    if "a" in str(rch):
        y = 100
        if "1" in str(rch):
            x = 100
        if "2" in str(rch):
            x = 100 + size
        if "3" in str(rch):
            x = 100 + size * 2
    if "b" in str(rch):
        y = 100 + size
        if "1" in str(rch):
            x = 100
        if "2" in str(rch):
            x = 100 + size
        if "3" in str(rch):
            x = 100 + size * 2
    if "c" in str(rch):
        y = 100 + size * 2
        if "1" in str(rch):
            x = 100
        if "2" in str(rch):
            x = 100 + size
        if "3" in str(rch):
            x = 100 + size * 2

    cv.create_oval(x,y,x+size,y+size)

Any help will be appreciated. Also, if you can find a way to make the mess in the tkO() function more efficient (shorter) that will help too.

Answer 1

The function is fixed, All I had to do was add a few more variables. making the if statements with `if "(letter)" in rch being strings and the if statements with class objects - objects (rchobject).

Thanks to Bryan Oakley for helping me figure this out!

import random as r

spots = (a1,a2,a3,b1,b2,b3,c1,c2,c3)
spotsStr = spots but with strings

def tkO():
 rn = r.randint(1,10)
 rch = spotsStr[rn]
 rchobject = spots[rn]