Raise exception vs. return None in functions?

Question

What\'s better practice in a user-defined function in Python: raise an exception or return None? For example, I have a function that finds the mos

Answer 1

In general, I'd say an exception should be thrown if something catastrophic has occured that cannot be recovered from (i.e. your function deals with some internet resource that cannot be connected to), and you should return None if your function should really return something but nothing would be appropriate to return (i.e. "None" if your function tries to match a substring in a string for example).