Python 最大值和最小值

Question

我对 Python 还是很陌生，让我对自己的问题感到生气的是，我觉得它真的很简单。我在第 8 行不断收到错误。我只想让这个程序获取用户输入的数字，然后打印最大和最小的，如果它们输入负1，我希望它取消循环。

'int' object is not iterable 是错误。

print "Welcome to The Number Input Program."

number = int(raw_input("Please enter a number: "))

while (number != int(-1)):
    number = int(raw_input("Please enter a number: "))

high = max(number)
low = min(number)

print "The highest number entered was ", high, ".\n"
print "The lowest number entered was ", low, ".\n"

raw_input("\n\nPress the enter key to exit.")

Answer 1

问题在于number 是int。 max 和 min 都需要列表（或其他可迭代的东西） - 因此，您必须将 number 添加到这样的列表中：

number = int(raw_input("Please enter a number: "))
num_list = []

while (number != int(-1)):
    num_list.append(number)
    number = int(raw_input("Please enter a number: "))

high = max(num_list)
low = min(num_list)

就像阅读 jimbob 博士的回答后的注释一样 - 我的回答假设您不想在找到 high 和 low 时想要考虑 -1。

Answer 2

这是因为每次你向 max 和 min 传递一个整数参数时，python 不知道如何处理它。

Ether 至少传递两个参数：

least_number = min(number1, number2,...,numbern)

或一个可迭代的：

least_number = min([number1, number2, ...,numbern])

这是doc

Answer 3

您需要将数字更改为数字列表。例如，

print "Welcome to The Number Input Program."

numbers = []
number = int(raw_input("Please enter a number: "))

while (number != -1):
    numbers.append(number)
    number = int(raw_input("Please enter a number: "))

high = max(numbers)
low = min(numbers)

print "The highest number entered was ", high, ".\n"
print "The lowest number entered was ", low, ".\n"

raw_input("\n\nPress the enter key to exit.")

Answer 4

正如another answer 所述，min 和 max 也可以采用多个参数。要省略列表，您可以

print "Welcome to The Number Input Program."

number = int(raw_input("Please enter a number: "))
high = low = number


while (number != int(-1)):
    number = int(raw_input("Please enter a number: "))
    high = max(high, number)
    low = min(low, number)

print "The highest number entered was ", high, ".\n"
print "The lowest number entered was ", low, ".\n"

raw_input("\n\nPress the enter key to exit.")

Answer 5

num = ''
active = True

largest = 0
smallest = 0
while active:
    num = input("Please enter a number")
    if num == 'done': 
        active = False
        break
    else:
        try:
            num = int(num)

            if largest < num:
                largest = num
            if smallest == 0 or smallest > num:
                smallest = num

        except ValueError:
            print("Please enter a valid number")

print("Largest no. is " + str(largest))
print("Smallest no. is " + str(smallest))