Decrease for loop by one

[Milter Skyler]

I'm using this code with Sikuli so thats why I have click()
    for x in range(0,10):
        decimal_value = random.randint(1,12)
        if myList.count(decimal_value) < 1:
            egg = 'A%d.png' % (decimal_value)
            egg = wait(egg)
            click(egg.getCenter().offset(random.randint(-10,10), random.randint(-10,10)))
            myList.append(decimal_value)

        else:
            print x
            x-1 = x
            print x

I made an array to check if the random integer already exists and then I send it to the else statement at which point I want to decrease x by 1 so that it doesn't count as one of the loops. In other languages this works but it just comes up with the output:

3
2

9
8

10
9