import cv2


face_cascade = cv2.CascadeClassifier("haarcascade_frontalface_default.xml")

img = cv2.imread("Screenshot from 2018-07-20 14-00-25.png")
gray_img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)

faces = face_cascade.detectMultiScale(gray_img,
                                      scaleFactor=1.05,
                                      minNeighbors=5)
for x, y, w, h in faces:
    img = cv2.rectangle(img, (x, y), (x+w, y+h), (0, 255, 0), 3)
# print(type(faces))
cv2.imshow("face_detector", img)
cv2.waitKey(0)
cv2.destroyAllWindows()