输入三个数值，输出其中的最大值和最小值

方法一：
print("Number1、Number2、Number3只能输入3个数字")

number1 = float(input("Number1= "))
number2 = float(input("Nnmber2= "))
number3 = float(input("Number3= "))

if number1 >= number2 >= number3:
    print("最大值为：",number1)
    print("最小值为：",number3)
elif number3 >= number1 >= number2:
    print("最大值为：",number3)
    print("最小值为：",number2)
elif number1 >= number3 >= number2:
    print("最大值为：",number1)
    print("最小值为：",number2)
elif number2 >= number1 >= number3:
    print("最大值为：",number2)
    print("最小值为：",number3)
elif number3 >= number2 >= number1:
    print("最大值为：",number3)
    print("最小值为：",number1)
else:
    print("最大值为：",number2)
    print("最小值为：",number1)

方法二：

print("Number1、Number2、Number3只能输入3个数字")

number1 = float(input("Number1= "))
number2 = float(input("Nnmber2= "))
number3 = float(input("Number3= "))
max_number = 0

if number1 >= number2:
    max_number = number1
    if number3 >= max_number:
        print("最大值为：",number3)
    else:
        print("最大值为：",max_number)
else:
    max_number = number2
    if number3 >= max_number:
        print("最大值为：", number3)
    else:
        print("最大值为：", max_number)