my print(“Found faces”, str(len(faces))) not executed

Question

I'm trying to detect multiple faces using opencv in python. I'm doing this in raspbian OS (raspberry Pi 3). Although the code is working properly, ie, it's detecting a face and drawing a rectangular boundary around the face. It successfully saves the image in my local folder as well. The problem is : the statement print("Found faces", str(len(faces))) isn't working and the console remains blank. What am I missing here or where am I going wrong?

import io
import picamera
import cv2
import numpy
stream = io.BytesIO()

with picamera.PiCamera() as camera:
    camera.resolution = (320, 240)
    camera.hflip = True
    camera.capture(stream, format='jpeg')


buff = numpy.fromstring(stream.getvalue(), dtype=numpy.uint8)

image = cv2.imdecode(buff, 1)

face_cascade = cv2.CascadeClassifier('face1.xml')

gray = cv2.cvtColor(image,cv2.COLOR_BGR2GRAY)

faces = face_cascade.detectMultiScale(gray, 1.1, 5)

print("Found faces", str(len(faces)))

for (x,y,w,h) in faces:
    cv2.rectangle(image,(x,y),(x+w,y+h),(255,255,0),2)

cv2.imwrite('result.jpg',image)

Answer 1

正确的代码是

print("Found faces= "+str(len(faces)))