def __init__(self, **kwargs):
    for k, v in kwargs.iteritems():
        setattr(self, k, v)

def __init__(self, **kwargs):
    self.__dict__.update( kwargs )

col = Varchar()
col.index = True
col.length = 255

col = Varchar(index = True, length = 255)

def __init__(self, **kwargs):
    valid_kwargs = ['x', 'y', 'z']
    for k, v in kwargs.iteritems():
        if k not in valid_kwargs:
            raise TypeError("Invalid keyword argument %s" % k)
        setattr(self, k, v)

class Hmm:
    def __init__(self, **kwargs):
        for k, v in kwargs.iteritems():
            setattr(self, k, v)
    def mymethod(self):
        print "mymethod should print this message.."

x = Hmm(mymethod = None)
x.mymethod() # raises TypeError: 'NoneType' object is not callable