Another problem

[noorulain3]

def calculateTransitions(im):
h, w = im.shape[0], im.shape[1]
prev = im[0,0]
n = 0
for x in range(1, h):
for y in range(1, w):
curr = im[x,y]
# check if the is black to white transition
n = n+1 if curr == 255 and prev == 0 else n
prev = curr
return n

There is something wrong with
n = n+1 if curr == 255 and prev == 0 else n
prev = curr
return n
this part

please solve getting the same error