gistfile1.txt

def parse_payload(data):
    assert data, "Invalid data to parse, it's empty."
    length, extra = data.split(':', 1)
    length = int(length)

    payload, extra = extra[:length], extra[length:]
    assert extra, "No payload type: %r, %r" % (payload, extra)
    payload_type, remain = extra[0], extra[1:]

    assert len(payload) == length, "Data is wrong length %d vs %d" % (length, len(payload))
    return payload, payload_type, remain

def parse_list(data):
    if len(data) == 0: return []

    result = []
    value, extra = parse_tnetstring(data)
    result.append(value)

    while extra:
        value, extra = parse_tnetstring(extra)
        result.append(value)

    return result

def parse_pair(data):
    key, extra = parse_tnetstring(data)
    assert extra, "Unbalanced dictionary store."
    value, extra = parse_tnetstring(extra)
    assert value, "Got an invalid value, null not allowed."

    return key, value, extra

def parse_dict(data):
    if len(data) == 0: return {}

    key, value, extra = parse_pair(data)
    result = {key: value}

    while extra:
        key, value, extra = parse_pair(extra)
        result[key] = value
  
    return result
    
def parse_tnetstring(data):
    payload, payload_type, remain = parse_payload(data)

    if payload_type == '#':
        value = int(payload)
    elif payload_type == '"':
        value = payload
    elif payload_type == '}':
        value = parse_dict(payload)
    elif payload_type == ']':
        value = parse_list(payload)
    else:
        assert False, "Invalid payload type: %r" % payload_type

    return value, remain

TESTS = {
    '0:}': {},
    '0:]': [],
    '34:5:hello"22:11:12345678901#4:this"]}': {'hello': [12345678901, 'this']},
    '5:12345#': 12345,
    '12:this is cool"': "this is cool",
    '0:"': "",
    '24:5:12345#5:67890#5:xxxxx"]': [12345, 67890, 'xxxxx'],
}

for data, expect in TESTS.items():
    payload, remain = parse_tnetstring(data)
    assert not remain, "Had trailing junk: %r" % remain
    assert payload != None, "Didn't get a payload."

    print "EXPECT", repr(expect), "GOT", repr(payload)