Most “pythonic” way of organising class attributes, constructor arguments and subclass constructor defaults?

Question

Being relatively new to Python 2, I\'m uncertain how best to organise my class files in the most \'pythonic\' way. I wouldn\'t be asking this but for the fact that Python se

Answer 1

• If attributes will vary from instance to instance make them instance attribute i.e. create them inside__init__ using self else if they need to be shared between class instances like a constant, put them at class level.

• If your class really need to pass, so many arguments in __init__, let derive class use argument list and keyword arguments e.g.

class Dog(ClassWithLotsOfAttributes):
    def __init__(self, *args , **kwargs):
        super(ClassWithLotsOfAttributes,    self).__init__(*args , **kwargs)
        self.coolness = "really cool!!!

• No need of passing all variables except few important ones, in __init__, class can assume some defaults and user can change them later on if needed.

• Use 4 spaces instead of tab.

• if you need to add an extra arg bite, to Dog and keyword arg old too

class CoolDog(ClassWithLotsOfAttributes):
    def __init__(self, bite, *args , **kwargs):
        self.old = kwargs.pop('old', False) # this way we can access base class args too
        super(ClassWithLotsOfAttributes,    self).__init__(*args , **kwargs)
        self.bite = bite
        self.coolness = "really really cool!!!

various ways you useCoolDog

CoolDog(True)
CoolDog(True, old=False)
CoolDog(bite=True, old=True)
CoolDog(old=True, bite=False)