Prepend every substructure of a nested dict/list structure with its path

prepend_with_path.py

def prepend_with_path(j, path=''):
    """
    >>> prepend_with_path({})
    [('', {})]
    >>> prepend_with_path([])
    [('', [])]
    >>> prepend_with_path({1:2})
    [('', {1: 2}), ('[1]', 2)]
    >>> prepend_with_path({'a':'b'})
    [('', {'a': 'b'}), ("['a']", 'b')]
    >>> prepend_with_path([1])
    [('', [1]), ('[0]', 1)]
    >>> prepend_with_path([{1:2}])
    [('', [{1: 2}]), ('[0]', {1: 2}), ('[0][1]', 2)]
    >>> prepend_with_path([0, {1:2}])
    [('', [0, {1: 2}]), ('[0]', 0), ('[1]', {1: 2}), ('[1][1]', 2)]
    """ 
    iterfuncs_by_type = {
        dict: dict.iteritems,
        list: enumerate,
    }   
    res = [(path, j)]
    type_of_j = type(j) 
    if type_of_j in iterfuncs_by_type:
        for k, v in iterfuncs[type_of_j](j):
            res += prepend_with_path(v, '%s[%r]' % (path, k))

    return res