partial_serve_flask_1.py

r = requests.get(url)
range_header = request.headers.get('Range', None)
if range_header:  # Client has requested for partial content
  size = int(r.headers.get('content-length'))  # Actual size of song

  # Look up for ranges
  m = re.search('(\d+)-(\d*)', range_header)
  g = m.groups()
  byte1, byte2 = 0, None
  if g[0]:
    byte1 = int(g[0])
  if g[1]:
    byte2 = int(g[1])
  length = size - byte1
  if byte2:
    length = byte2 + 1 - byte1
  data = r.content[byte1: byte2]  # Trim the data from server
  
  # Prepare response
  rv = Response(data, 206, mimetype=mime, direct_passthrough=True)
  rv.headers.add('Content-Range', 'bytes {0}-{1}/{2}'.format(byte1, byte1 + length - 1, size))
  return rv

# No partial content, handle normally