python - How to access the property of an object that was created dynamically using __getattr__ -

i have classes of resources:

class tokens():     def __init__(self, a, b):         self.a =         self.b = b      def create(self):         return "tokens resource"   class users():     def __init__(self, a, b):         self.a =         self.b = b      def create(self):         return "users resource" 

i have client class:

class client():     def __init__(self, account, password):         self.account = account         self.password = password      def __getattr__(self, attr):         self.__dict__[attr] = globals()[str.capitalize(attr)]("a", "b") 

using class want create client object lazy-loading attributes. unfortunately, exception first time. second time ok:

>>> client = client("account", "password") >>> print client.tokens.create() traceback (most recent call last):   file "<stdin>", line 1, in <module> attributeerror: 'nonetype' object has no attribute 'create' >>> print client.tokens.create() tokens resource 

what doing wrong?

you never returning created attribute:

def __getattr__(self, attr):     self.__dict__[attr] = globals()[str.capitalize(attr)]("a", "b")     return self.__dict__[attr] 

you set attribute in self.__dict__, next attempt access finds attribute , never calls __getattr__ again.

i'm not sure why using str.capitalize() unobund method when can call on attr directly:

def __getattr__(self, attr):     self.__dict__[attr] = globals()[attr.capitalize()]("a", "b")     return self.__dict__[attr]