code: def retry(ExceptionToCheck, tries=4, delay=3, backoff=2, logger=None):
      
      def deco_retry(f):
  
          @wraps(f)
          def f_retry(*args, **kwargs):
              mtries, mdelay = tries, delay
              while mtries > 1:
                  try:
                      return f(*args, **kwargs)
                  except ExceptionToCheck as e:
                      msg = "%s, Retrying in %d seconds..." % (str(e), mdelay)
                      if logger:
                          logger.warning(msg)
                      else:
                          print(msg)
                      time.sleep(mdelay)
                      mtries -= 1
                      mdelay *= backoff
              return f(*args, **kwargs)
  
          return f_retry  # true decorator
  
      return deco_retry
docs: Retry calling the decorated function using an exponential backoff.
      original from: http://wiki.python.org/moin/PythonDecoratorLibrary#Retry
  
      :param ExceptionToCheck: the exception to check. may be a tuple of
          exceptions to check
      :type ExceptionToCheck: Exception or tuple
      :param tries: number of times to try (not retry) before giving up
      :type tries: int
      :param delay: initial delay between retries in seconds
      :type delay: int
      :param backoff: backoff multiplier e.g. value of 2 will double the delay
          each retry
      :type backoff: int
      :param logger: logger to use. If None, print
      :type logger: logging.Logger instance