Saving images using Opencv in python
A very simple change that replaces the while loop with a for loop (I don't know much about OpenCV, so I can't help too much there):

for count in range(1, 10):
    _, pho = webcam.read()
    gr = cv2.cvtColor(im, cv2.COLOR_BGR2GRAY)
    images = face_cascade.detectMultiScale(gr, 1.3, 4)
    for (x,y,w,h) in faces: 
            cv2.rectangle(pho,(x,y),(x+w,y+h),(0,255,0),2)
            fa = gray[y:y + h, x:x + w]
            e_size = cv2.resize(fa, (100, 100))
            cv2.imwrite('%s/%s.JPEG' % (folder,count), e_size)
    cv2.imshow('OpenCV', pho)
    key = cv2.waitKey(20)  


Additionally, in Python 3 especially, the % string formatting syntax is out-of-favor/deprecated -- use the {} and .format syntax instead:

cv2.imwrite('%s/%s.JPEG' % (folder,count), e_size)


becomes

cv2.imwrite('{!s}/{!s}.JPEG'.format(folder, count), e_size)