with open(str(cameraId) + '-datay.json', 'w') as f:
json.dump(startPositions, f)
with open(filename) as f:
cameraId = int(filename.split('-')[0])
startPositions = json.load(f)
with open(str(cameraId) + '-datay.json', 'w') as f:
json.dump(startPositions, f)
with open(filename) as f:
cameraId = int(filename.split('-')[0])
startPositions = json.load(f)