new_contents: import cv2
  import sys
  
  #cascPath = sys.argv[1]
  #faceCascade = cv2.CascadeClassifier(cascPath)
  faceCascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
  video_capture = cv2.VideoCapture(0)
  
  while True:
      # Capture frame-by-frame
      ret, frame = video_capture.read()
  
      gray = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY)
  
      faces = faceCascade.detectMultiScale(
          gray,
          scaleFactor=1.1,
          minNeighbors=5,
          minSize=(30, 30),
          flags=cv2.CASCADE_SCALE_IMAGE
      )
  
      # Draw a rectangle around the faces
      for (x, y, w, h) in faces:
          cv2.rectangle(frame, (x, y), (x+w, y+h), (0, 255, 0), 2)
  
      # Display the resulting frame
      cv2.imshow('Video', frame)
  
      if cv2.waitKey(1) & 0xFF == ord('q'):
          break
  
  # When everything is done, release the capture
  video_capture.release()
  cv2.destroyAllWindows()
  
subject: Create face_detect.py