(self)
return [f for f in self.fields if f not in self.keys]
returns fields not in keys
returns fields not in keys
returns fields not in keys
def nonkeys(self):
        """returns fields not in keys"""
        return [f for f in self.fields if f not in self.keys]
def nonkeys ( self ) : return [ f for f in self . fields if f not in self . keys ]