main.py

import cv2
import sys
import os

cascPath = os.getcwd()+'/haarcascades/haarcascade_frontalface_alt2.xml'

faceCascade = cv2.CascadeClassifier(cascPath)

video_capture =cv2.VideoCapture(0)

while True:
    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
    )

    #this draws the rectangle
    for (x,y,w,h,) in faces:
        cv2.rectangle(frame, (x,y), (x+w, y+h), (0, 255, 0), 2)
    
    cv2.imshow('Video', frame)

    if cv2.waitKey(1) & 0xFF == ord('q'):
        break

video_capture.release()
cv2.destroyAllWindows()