code: def from_url(cls, db_url=ALL_SETS_ZIP_URL):
          
          r = requests.get(db_url)
          r.raise_for_status()
  
          if r.headers['content-type'] == 'application/json':
              return cls(json.loads(r.text))
  
          if r.headers['content-type'] == 'application/zip':
              with zipfile.ZipFile(six.BytesIO(r.content), 'r') as zf:
                  names = zf.namelist()
                  assert len(names) == 1, 'One datafile in ZIP'
                  return cls.from_file(io.TextIOWrapper(
                      zf.open(names[0]),
                      encoding='utf8'))
docs: Load card data from a URL.
  
          Uses :func:`requests.get` to fetch card data. Also handles zipfiles.
  
          :param db_url: URL to fetch.
          :return: A new :class:`~mtgjson.CardDb` instance.