Python：如何迭代嵌套在while循环中的列表？

我有以下代码：

shape = input("Please enter your choice of shape? ")    

nthTime = ["second","third","fourth","fifth","sixth"]

while shape.lower() not in ["octagon","heptagon","hexagon"] :
    print("Please select a shape from the list!")
    shape = input("Pick a shape, for the " + nthTime + " time! ")

我如何才能实现这样的结果，即Python每次通过“while”循环时都会遍历列表“nthTime”

我可以使用嵌套for循环，但这当然会运行整个列表，这不是我的目标

因此，我得出结论，我需要使用嵌套的while循环；但是，我无法理解确切的语法

我希望这在将来对其他人也是一个有用的问题

类似这样：

nthTime.reverse()

while shape.lower() not in ["octagon","heptagon","hexagon"] and nthTime:
    print("Please select a shape from the list!")
    shape = input("Pick a shape, for the " + nthTime.pop() + " time! ")

shape = input("Please enter your choice of shape? ")    

nthTime = ["second","third","fourth","fifth","sixth"]
undesired_shapes = ["octagon","heptagon","hexagon"]

indx = 0

while shape.lower() not in undesired_shapes:
    print("Please select a shape from the list!")
    shape = input("Pick a shape, for the " + nthTime[indx] + " time! ")
    indx += 1
    if indx >= len(nthTime):
        print 'Giving up !!'
        break

---

仅当用户输入正确的值时，才使用for循环和中断循环

for iteration in nthTime:
    if shape.lower() not in ["octagon","heptagon","hexagon"]:
        print("Please select a shape from the list!")
        shape = input("Pick a shape, for the " + iteration + " time! ")
    else: break
else: print "You have wasted all your chances, try again later"

---

每次通过while循环时，while over

nthTime

下的嵌套for循环都会在列表上迭代。您的问题是什么？我想您可能需要类似于

shape=input（“为“+nthTime[iteration\u index]+”time！”选择一个形状）

？您不需要反转列表，基本上使其成为一个堆栈……无需反转。您可以简单地执行

nthTime.pop（0）

，或者他可以按照正确的顺序定义字符串文本。这是一个无关紧要的问题，我倒过来尽量减少对代码的更改。我在向他演示如何使用堆栈来完成尝试。谢谢。是否可以使用while循环在列表上进行迭代？