在函数中引发什么异常以表示不满足先决条件?
例子:
def print_stats(name, age):
if name is None:
raise Exception("name cannot be None")
if not type(name) is str:
raise Exception("name must be a string")
if age is None:
raise Exception("age cannot be None")
if age < 0:
raise Exception("age cannot be negative")
print("{0} is {1} years old".format(name, age))
请您参考如下方法:
您应该同时使用 TypeError 和 ValueError。
前三个异常应该是TypeError,因为我们表示参数的类型不正确。来自docs :
exception
TypeErrorRaised when an operation or function is applied to an object of inappropriate type. The associated value is a string giving details about the type mismatch.
然而,最后一个异常应该是 ValueError,因为 age 是正确的类型但具有不正确的值(它是负数)。来自docs :
exception
ValueErrorRaised when a built-in operation or function receives an argument that has the right type but an inappropriate value, and the situation is not described by a more precise exception such as
IndexError.
