Example usage

In [1]: from schema_object import SchemaObject

In [2]: class Person(SchemaObject):
   ...:     first_name = None
   ...:     last_name = None
   ...:     email = None
   ...:     

In [3]: Person()
Out[3]: Person()

In [4]: Person(first_name='Foo', last_name='Bar')
Out[4]: Person(first_name='Foo', last_name='Bar')

In [5]: Person(invalid='something')
---------------------------------------------------------------------------
AttributeError                            Traceback (most recent call last)
<ipython-input-5-70a7a2cc4ef9> in <module>()
----> 1 Person(invalid='something')

/tmp/tmp.TbiZ1MuzjJ/schema_object.py in __init__(self, **attrs)
      3     def __init__(self, **attrs):
      4         for key, val in attrs.items():
----> 5             setattr(self, key, val)
      6 
      7     def __setattr__(self, name, value):

/tmp/tmp.TbiZ1MuzjJ/schema_object.py in __setattr__(self, name, value)
      6 
      7     def __setattr__(self, name, value):
----> 8         getattr(self, name)  # raise AttributeError if not set
      9         super().__setattr__(name, value)
     10 

AttributeError: 'Person' object has no attribute 'invalid'

schema_object.py

class SchemaObject:

    def __init__(self, **attrs):
        for key, val in attrs.items():
            setattr(self, key, val)

    def __setattr__(self, name, value):
        getattr(self, name)  # raise AttributeError if not set
        super().__setattr__(name, value)

    def __repr__(self):
        myname = self.__class__.__name__
        args = ', '.join('{}={}'.format(key, repr(value))
                         for key, value in self.__dict__.items())
        return '{}({})'.format(myname, args)