为什么当我输入整数时它显示为不是整数？ （Python）[重复]

Question

如您所知，我是一个相当新手的 Python 编码器。截至目前，我只是在制作一些小测试程序，并试图确保我的所有缩进以及在尝试任何大型程序之前都正确完成。 所以我试图确保如果输入不是整数，那么程序会输出一条消息，说明必须输入整数。但是，对于我拥有的当前代码（我认为应该是正确的），无论答案如何，都会输出“请输入整数”消息。我做错了什么？代码如下：

a = input("What is your age?")
b = 7
c = ((a-2) * 4) +25
if a == int:
    print "Your age in a small dog's years is:", ((a-2) * 4)+28
    print "Your age in a medium sized dog's years is:", ((a-2) * 6)+27
    print "Your age in a big dog's years is:", ((a-2) * 9)+22
    print "Your age in cat years is:", c
    print "Your age in guinea pig years is:", a * 15
    print "Your age in hamster years is:", a * 20
    print "Your age in pig years is:", ((a-1) * 4)+18
    print "Your age in goldfish years is:", ((a-1) * 8)+188
    print "Your age in cow years is:", ((a-1) * 4)+14
    print "Your age in horse years is:", a * 3
    print "Your age in goat years is:", ((a-1) * 6)+18
    print "Your age in rabbit years is:", ((a-1) * 8)+20
    print "Your age in chinchilla years is:", ((a-1) * 7)+17
elif a != int:
    print "You must enter an integer!"

否则它会起作用，只是这个小结尾的两行似乎毁了它。 谢谢。

Answer 1

Python 3：

a = input("What is your age?") # this is a string input
a = int(input("What is your age?")) # you need an integer input
elif(isinstance(a, int)) # this is how you check if a is integer

对于您在 Python 2 中的情况：

a = raw_input("What is your age?") # input is interpreted as unicode here

try:
  a = int(a)
  b = 7
  c = ((a-2) * 4) +25
  print "Your age in a small dog's years is:", ((a-2) * 4)+28
except:
  print "You must enter an integer!"