gistfile1.py

class Values:

    def __init__(self, defaults=None):
        if defaults:
            for (attr, val) in defaults.items():
                setattr(self, attr, val)

    def __str__(self):
        return str(self.__dict__)

    __repr__ = _repr

    def __eq__(self, other):
        if isinstance(other, Values):
            return self.__dict__ == other.__dict__
        elif isinstance(other, dict):
            return self.__dict__ == other
        else:
            return NotImplemented

    def _update_careful(self, dict):
        """
        Update the option values from an arbitrary dictionary, but only
        use keys from dict that already have a corresponding attribute
        in self.  Any keys in dict without a corresponding attribute
        are silently ignored.
        """
        for attr in dir(self):
            if attr in dict:
                dval = dict[attr]
                if dval is not None:
                    setattr(self, attr, dval)

    def _update_loose(self, dict):
        """
        Update the option values from an arbitrary dictionary,
        using all keys from the dictionary regardless of whether
        they have a corresponding attribute in self or not.
        """
        self.__dict__.update(dict)

    def _update(self, dict, mode):
        if mode == "careful":
            self._update_careful(dict)
        elif mode == "loose":
            self._update_loose(dict)
        else:
            raise ValueError("invalid update mode: %r" % mode)

    def read_module(self, modname, mode="careful"):
        __import__(modname)
        mod = sys.modules[modname]
        self._update(vars(mod), mode)

    def read_file(self, filename, mode="careful"):
        vars = {}
        exec(open(filename).read(), vars)
        self._update(vars, mode)


    def ensure_value(self, attr, value):
        if not hasattr(self, attr) or getattr(self, attr) is None:
            setattr(self, attr, value)
        return getattr(self, attr)