import cv2

# face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_default.xml')
face_cascade = cv2.CascadeClassifier('haarcascade_frontalface_alt.xml')

img = cv2.imread('girlsday1.jpg')

faces = face_cascade.detectMultiScale(img, 1.1, 3)
for (x,y,w,h) in faces:
    img = cv2.rectangle(img,(x,y),(x+w,y+h),(255,0,0),2)

cv2.imshow('img',img)
cv2.waitKey(0)
cv2.destroyAllWindows()