def roundrobin()

in reader/utils.py [0:0]

• 15 lines of code
• 6 McCabe index (conditional complexity)

def roundrobin(*iterables):
  """Round robin through provided iterables, useful for simple load balancing.

  Adapted from https://docs.python.org/3/library/itertools.html.

  """
  num_active = len(iterables)
  nexts = itertools.cycle(iter(it).__next__ for it in iterables)
  while num_active:
    try:
      for _next in nexts:
        result = _next()
        yield result
    except StopIteration:
      # Remove the iterator we just exhausted from the cycle.
      num_active -= 1
      nexts = itertools.cycle(itertools.islice(nexts, num_active))
      logging.warning(f"Iterable exhausted, {num_active} iterables left.")
    except Exception as exc:
      logging.warning(f"Iterable raised exception {exc}, ignoring.")
      # continue
      raise