How to change behavior of dict() for an instance

Question

So I\'m writing a class that extends a dictionary which right now uses a method \"dictify\" to transform itself into a dict. What I would like to do instead though is change it

Answer 1

Do you want just to print it like a dict ? use this:

from collections import defaultdict

class RecursiveDict(defaultdict):
    '''
    A recursive default dict.

    >>> a = RecursiveDict()
    >>> a[1][2][3] = 4
    >>> a.dictify()
    {1: {2: {3: 4}}}
    >>> dict(a)
    {1: {2: {3: 4}}}

    '''
    def __init__(self):
        super(RecursiveDict, self).__init__(RecursiveDict)

    def dictify(self):
        '''Get a standard dictionary of the items in the tree.'''
        return dict([(k, (v.dictify() if isinstance(v, dict) else v))
                     for (k, v) in self.items()])

    def __dict__(self):
        '''Get a standard dictionary of the items in the tree.'''
        print [(k, v) for (k, v) in self.items()]
        return dict([(k, (dict(v) if isinstance(v, dict) else v))
                     for (k, v) in self.items()])

    def __repr__(self):
        return repr(self.dictify())

Maybe you are looking for __missing__ :

class RecursiveDict(dict):
    '''
    A recursive default dict.

    >>> a = RecursiveDict()
    >>> a[1][2][3] = 4
    >>> a
    {1: {2: {3: 4}}}
    >>> dict(a)
    {1: {2: {3: 4}}}

    '''

    def __missing__(self, key):
        self[key] = self.__class__()
        return self[key]