I'm Bad, forgot to run camera.release()

So there I am happily working along and then run into a ditch because I forgot to run camera.release()
Other than rebooting is there better way to restore order? Perhaps by running some system command?

As I understand it when

camera = cv2.VideoCapture(0)

is executed a file is generated into which the image is placed. Where is that file?

This is more related to opencv so maybe have a look at the opencv documentation?