import sys


class Structure:
    _fields = ()

    @staticmethod
    def _init():
        locs = sys._getframe(1).f_locals
        self = locs.pop('self')
        for name, val in locs.items():
            setattr(self, name, val)

    def __repr__(self):
        args = map(lambda field: f"{field}={getattr(self, field)!r}", self._fields)
        return f"{type(self).__name__}({', '.join(args)})"

    def __setattr__(self, name, value):
        if name in self._fields or name[0] == '_':
            super().__setattr__(name, value)
        else:
            raise AttributeError(f"No attribute {name}")