gistfile1.py

def dictpath(dct, path):
    """Resolve dictpath
    >>> r = {'also_viewed': ['url1', 'url2']}
    >>> list(dictpath(r, 'also_viewed'))
    ['url1', 'url2']
    >>> r = {'related': [{'url': 'url1'}, {'url': 'url2'}]}
    >>> list(dictpath(r, 'related:url'))
    ['url1', 'url2']
    >>> r = {'related': [{'urls': ['url1', 'url2']}, {'urls': ['url3', 'url4']}]}
    >>> list(dictpath(r, 'related:urls'))
    ['url1', 'url2', 'url3', 'url4']
    >>> r = {'related': [['name1', 'url1', 'image1'], ['name2', 'url2', 'image2']]}
    >>> list(dictpath(r, 'related[1]'))
    ['url1', 'url2']
    >>> r = {'related': [['name1', 'url1', 'url2'], ['name2', 'url3', 'url4']]}
    >>> list(dictpath(r, 'related[1:3]'))
    ['url1', 'url2', 'url3', 'url4']
    >>> list(dictpath(r, 'related[1:]'))
    ['url1', 'url2', 'url3', 'url4']
    >>> r = {'related': [['url1', 'url2'], ['url3', 'url4']]}
    >>> list(dictpath(r, 'related[:]'))
    ['url1', 'url2', 'url3', 'url4']
    >>> r = {'related': [['url1', 'name1'], ['url2', 'name2']]}
    >>> list(dictpath(r, 'related[:-1]'))
    ['url1', 'url2']
    """
    lex = shlex.shlex(path)
    lex.wordchars += '-'
    rr = dct
    for token in lex:
        if token == ':':
            continue
        elif token == '[':
            assert isinstance(rr, list), 'Dicts can\'t be sliced'
            slice_args  = []
            last_token = None
            for token in lex:
                if token == ']':
                    if last_token == ':':
                        slice_args.append(None)
                    break
                if token == ':':
                    if not slice_args:
                        slice_args.append(None)
                else:
                    slice_args.append(int(token))
                last_token = token

            if len(slice_args) == 1:
                slice_args = [slice_args[0], slice_args[0] + 1]
            slice_obj = slice(*slice_args)
            if rr and isinstance(rr[0], list):
                rr = [itemgetter(slice_obj)(x) for x in rr]
            else:
                rr = itemgetter(slice_obj)(rr)
        else:
            if isinstance(rr, dict):
                if token not in rr:
                    break
                rr = rr[token]
            elif isinstance(rr, list):
                rr = [x[token] for x in rr if token in x]
                if not rr:
                    break
    else:
        if isinstance(rr, basestring):
            rr = [rr]
        if isinstance(rr, list):
            for url in flatten(rr):
                yield url