python 3.3.2 年龄 >= 24 : TypeError: unorderable types: str() >= int()

Question

print("how old are you")
age = input(">")
if age >= 24:
print("you are getting old")
print (age)
else:
print("i don't care")
print (age)

这是我遇到的错误:

if age >= 24:
TypeError: unorderable types:     str() >= int()

Answer 1

在 Python 3 上，input() 总是 返回一个字符串值。使用 int() type转换它:

if int(age) >= 24:

字符串值和 int 不可排序:

>>> '24' > 23
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unorderable types: str() > int()

请注意，如果无法转换输入，int() 会抛出一个ValueError 异常:

>>> int('Why do you want to know my age?')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: invalid literal for int() with base 10: 'Why do you want to know my age?'