code: def search(self, regex, flags=0):
          
          return self._generate_test(
              lambda value: re.search(regex, value, flags),
              ('search', self._path, regex)
          )
docs: Run a regex test against a dict value (only substring string has to
          match).
  
          >>> Query().f1.search(r'^\w+$')
  
          :param regex: The regular expression to use for matching