Loop through all nested dictionary values?

As said by Niklas, you need recursion, i.e. you want to define a function to print your dict, and if the value is a dict, you want to call your print function using this new dict.

Something like :

def myprint(d):
    for k, v in d.items():
        if isinstance(v, dict):
            myprint(v)
        else:
            print("{0} : {1}".format(k, v))

Since a dict is iterable, you can apply the classic nested container iterable formula to this problem with only a couple of minor changes. Here's a Python 2 version (see below for 3):

import collections
def nested_dict_iter(nested):
    for key, value in nested.iteritems():
        if isinstance(value, collections.Mapping):
            for inner_key, inner_value in nested_dict_iter(value):
                yield inner_key, inner_value
        else:
            yield key, value

Test:

list(nested_dict_iter({'a':{'b':{'c':1, 'd':2}, 
                            'e':{'f':3, 'g':4}}, 
                       'h':{'i':5, 'j':6}}))
# output: [('g', 4), ('f', 3), ('c', 1), ('d', 2), ('i', 5), ('j', 6)]

In Python 2, It might be possible to create a custom Mapping that qualifies as a Mapping but doesn't contain iteritems, in which case this will fail. The docs don't indicate that iteritems is required for a Mapping; on the other hand, the source gives Mapping types an iteritems method. So for custom Mappings, inherit from collections.Mapping explicitly just in case.

In Python 3, there are a number of improvements to be made. As of Python 3.3, abstract base classes live in collections.abc. They remain in collections too for backwards compatibility, but it's nicer having our abstract base classes together in one namespace. So this imports abc from collections. Python 3.3 also adds yield from, which is designed for just these sorts of situations. This is not empty syntactic sugar; it may lead to faster code and more sensible interactions with coroutines.

from collections import abc
def nested_dict_iter(nested):
    for key, value in nested.items():
        if isinstance(value, abc.Mapping):
            yield from nested_dict_iter(value)
        else:
            yield key, value

Alternative iterative solution:

def myprint(d):
    stack = d.items()
    while stack:
        k, v = stack.pop()
        if isinstance(v, dict):
            stack.extend(v.iteritems())
        else:
            print("%s: %s" % (k, v))

Slightly different version I wrote that keeps track of the keys along the way to get there

def print_dict(v, prefix=''):
    if isinstance(v, dict):
        for k, v2 in v.items():
            p2 = "{}['{}']".format(prefix, k)
            print_dict(v2, p2)
    elif isinstance(v, list):
        for i, v2 in enumerate(v):
            p2 = "{}[{}]".format(prefix, i)
            print_dict(v2, p2)
    else:
        print('{} = {}'.format(prefix, repr(v)))

On your data, it'll print

data['xml']['config']['portstatus']['status'] = u'good'
data['xml']['config']['target'] = u'1'
data['xml']['port'] = u'11'

It's also easy to modify it to track the prefix as a tuple of keys rather than a string if you need it that way.