import json
from urllib import request, error

data = json.dumps({
    "frame_id": 1,
    "engine": "base_model",
    "threshold": 0.35,
    "iou_threshold": 0.8,
    "min_box_frac": 0.0,
    "target_class_names": []
}).encode('utf-8')

req = request.Request('http://127.0.0.1:8000/api/batches/1/preview', data=data, headers={'Content-Type': 'application/json'})
try:
    with request.urlopen(req) as response:
        print(response.read().decode('utf-8'))
except error.HTTPError as e:
    print(f"HTTPError: {e.code}")
    print(e.read().decode('utf-8'))
except Exception as e:
    print(f"Error: {e}")