code: def timestamp(method='iso8601'):
      
      if method == 'iso8601':
          # ISO 8601
          # datetime.datetime.utcnow().isoformat()
          # datetime.datetime.now().isoformat()
          # utcnow
          tz_hour = time.timezone // 3600
          utc_offset = str(tz_hour) if tz_hour < 0 else '+' + str(tz_hour)
          stamp = time.strftime('%Y-%m-%dT%H%M%S') + utc_offset
          return stamp
      else:
          raise ValueError('only iso8601 is accepted for now')
docs: make an iso8601 timestamp
  
      Args:
          method (str): type of timestamp
  
      Example:
          >>> stamp = timestamp()
          >>> print('stamp = {!r}'.format(stamp))
          stamp = ...-...-...T...