coursesera stack sequence solver

gistfile1.txt

source = list(range(10))
stack = []

expected = [6, 5, 4, 3, 2, 1, 0, 7, 8, 9]

while expected:
    while not stack or stack[0] != expected[0]:
        stack.insert(0, source.pop(0))
        print("push", stack[0])
    print("pop", stack[0])
    stack.pop(0)
    expected.pop(0)
print("done")