title: Status code 400 when posting multiple lists
body: <p>I am working with YOLOv5 framework and I am trying to POST coordinates of a bounding box to an API server. The problem occurs when I am trying to post the coordinates of a bounding box as a list. Essentially I am trying to implement the following structure:</p>
  <pre><code>Boxes: [{x,y,w,h},
  {x,y,w,h},
  {x,y,w,h},
  {x,y,w,h}]
  </code></pre>
  <p><strong>main.py</strong></p>
  <pre><code>            command = input('Enter command for a snap')
              if command == 'n':
                  for *xyxy, conf, cls in reversed(det):
                      c1, c2 = (int(xyxy[0]), int(xyxy[1])), (int(xyxy[2]), int(xyxy[3]))
  
                      center_point = round((c1[0]+c2[0])/2), round((c1[1]+c2[1])/2)
                      circle = cv2.circle(im0, center_point,5,(0,255,0),2)
                      text_coord = cv2.putText(im0,str(center_point), center_point,cv2.FONT_HERSHEY_PLAIN,2,(0,0,255))
  
  
  
                      # print(x_coord, y_coord, w_coord, h_coord)
                      # print(center_point)
                      x_coord = [c1[0]]
                      y_coord = [c1[1]]
                      w_coord = [c2[0] - c1[0]]
                      h_coord = [c2[1] - c1[1]]
  
                      boxes = x_coord + y_coord + w_coord + h_coord
  
                      data = {
                          'Boxes': boxes,
                      }
                      json_object = json.dumps(data, indent=4)
  
                      r = requests.post(
                          &quot;http://127.0.0.1:8000/snippets/&quot;,
                          data=(json_object),
                          headers={'Authorization': 'Token 353101b2657b3779199777984c131f33b78656be',
                                   &quot;Content-Type&quot;: &quot;application/json&quot;},
                      )
                      print(r.status_code)
  </code></pre>
  <p>Thanks in advance</p>