小编Gab*_*Lee的帖子

我最近参加了一门 Python 课程，我正在做的练习希望我找到最大和最小的数字。如果我输入一个“字符串”，那么它会提示“无效输入”。这是我到目前为止所得到的，但我收到了回溯错误：

Traceback (most recent call last):
    File "FindingSmallestLargestNum.py", line 15, in <module>
    if num > largest:
TypeError: '>' not supported between instances of 'float' and 
'NoneType'

这是我的代码行：

largest = None
smallest = None

while True: 
    num = input("Enter a number: ")
    if num == "done": break
    try:
        num = float(num)
except:
    print("Invalid input")
    continue

    if smallest is None:
        smallest = num
    if num > largest:
        largest = num
    elif num < smallest:
        smallest = num

print("Maximum is",int(largest))
print("Minimum …