import cv2

cascade = 'cars.xml'
video = 'cars.mp4'

cap = cv2.VideoCapture(video)

car_cascade = cv2.CascadeClassifier(cascade)



while True:
    Success,image = cap.read()
    
    gary = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY)
    
    cars = car_cascade.detectMultiScale(gary,1.1,1)
    
    for (x,y,w,h) in cars:
        cv2.rectangle(image,(x,y),(x+w,y+h),(0,0,255),2)
        
    cv2.imshow('cars', image)
    
    if cv2.waitKey(33) == 27:
        break
    
cv2.destroyAllWindows()