When programming in C# I usually write following arguments validation code:
void Process(object item) {
if (item == null) throw ArgumentNullException();
// code
}
Is it 'Pythonic' to do similar validation in Python? I really don't want anybody pass None to Process method. What type of Python Exception should I use? (There are no standard ArgError or something like this)
def Process(item):
if item == None: raise ArgNoneError('item')
# code
Thanks
Usually, you'd just try to make do with the arguments you got -- if someone passes None to your function it will fail anyway. There is no need to add complexity to your code without any benefit. Quite the contrary -- often such tests prevent your code from working for cases it would work fine wwithout the tests.
If you want to raise some error anyway, use TypeError -- it is meant for this purpose.
initialize method, which only saves passed arguments into class attributes, so it does not fail if someone passes None (but call to other methods will fail), thats why I want to add some validation.
Use TypeError:
exception TypeError
Raised 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.
