Returning a list/dict as "read-only" from a method ?

[Sean Ross]

The following is a possible solution. However, it does not return a
list/dict as read-only from a method.
Rather, it wraps your list/dict in a read-only property.

Also, I only deal with data as a dictionary, not as a list. But, it's the
same idea.

class C:
    def __init__(self):
        # here we're just dealing with self.__data as a dict
        self.__data = { "hello": "world", "how":"are", "you":"today"}
    def get_data(self):
        return lambda key: self.__data[key]
    def get_keys(self):
        return self.__data.keys()
        # if self.__data is a list, return range(len(self.__data))
    data = property(get_data)
    keys = property(get_keys)

if __name__ == "__main__":
    inst = C()
    for key in inst.keys:
        print "inst.data[%s]: %s " % (key, inst.data(key))

Hope this helps,
Sean