dict_delta.py

def dict_delta(old, new):
    """
    Compute the differences between two versions of a dictionary
    
    >>> dict1 = {\
        'ipsum': 'ABC',\
        'dsqdq': 'sssdqs',\
        'opapoaaz': 'dpqsnqsd',\
        'pPlolf': 'popoazn',\
        'pfkv': 'blah',\
    }
    >>> dict2 = {\
        'ipsum': 'ABl',\
        'dsqdq': 'sssdqs',\
        'hereiam': 'test',\
        'opapoaaz': 'dpqsnqsd',\
        'pPlolf': 'popoazn',\
    }
    >>> dict_delta(dict1, dict2)
    [('pfkv', '-'), ('ipsum', '*', 'ABl'), ('hereiam', '+', 'test')]
    """
    diff = []
    new_items = new.keys()
    
    for old_item in old.keys():
        if not old_item in new:
            diff.append((old_item, '-'))
        else:
            new_items.remove(old_item)
            new_value = new[old_item]
            if not old[old_item] == new_value:
                diff.append((old_item, '*', new_value))
    for new_item in new_items:
        diff.append((new_item, '+', new[new_item]))
    
    return diff