[英]is 'if top==None:top=1' correct
I don't understand why the top
variable in the append
function is greyed out.我不明白为什么
append
function 中的top
变量是灰色的。 No matter what I do, the value of top
stays None.无论我做什么,
top
的值都保持为 None。 This is the output .这是 output 。 I also tried using 0 instead of None and I still have the same problem.
我也尝试使用 0 而不是 None ,但我仍然遇到同样的问题。 I've included the code below.
我已经包含了下面的代码。
top = None
stack = []
def append(a, top):
stack.append(a)
if top == None:
top = 1
else:
top += 1
def pop(top):
if top == None:
print('underflow error encountered')
else:
print('the popped element is:', poppedele)
print(top)
while True:
kk = input('wat do you want to do ....')
if kk == '1':
a = input('enter the element to append')
append(a, top)
print(stack, top)
elif:
pop(top)
print(stack, top)
else:
break
Here's a screenshot of what it looks like:这是它的截图:
Thanks @aarni joensuu.谢谢@aarni joensuu。 Turns out I should add global top in those functions only then the change will be made to the overall variable.
原来我应该在这些函数中添加全局顶部,然后才会对整体变量进行更改。
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.