I have a class being created and I'm testing the arguments when the
class is called. Within the class can I error out if the types are
wrong and prevent the class from returning? How do you guys handle
this?
what do you mean by "class is called" ? __init__() ? __call__() ? custom
methods?
like already said, exceptions are the right way to handle execution flow
when errors occur.
usually if you need to do some error checking for argument, you got to
make sure there's only one
way for data to enter, e.g. this is two ways for data to enter, you'd
have to check at two places:
class Person:
def __init__(self,name):
# name comes unchecked here
self.name = name
def setName(self,name)
if name is None:
raise BadNameException,'name cannot be empty'
if len(name)<2:
raise BadNameException,'name is too short'
self.name = name
to fix that, you'd need to go with a lightweight constructor (with no
arguments), or use setName() in costructor to
initialize data.
notice there's no problem with inheriting classes:
class PersonInDatabase(Person)
def __init__(self,id):
# constructor will fail if setting invalid name from database
self.setName(Database.loadPersonName(id))
--
http://groups.google.com/group/python_inside_maya
