使用Python计算黑色像素

Question

I am in my first programming class so very new. I'm trying to count the black pixels in a picture and I'm stuck. This is what I have so far:

def main():
#create a 10x10 black picture
 newPict = makeEmptyPicture(10, 10)
 show(newPict)
 setAllPixelsToAColor(newPict,black)
 #Display the picture
 show(newPict)
 #Initialize variabl countBlack to 0 
 countZero = 0
 for p in getPixels(newPict):
     r = getRed(p)
     b = getBlue(p)
     g = getGreen(p)
     if (r,g,b) == (0,0,0):
        countZero = countZero + 100
     return countZero

Answer 1

How it was pointed by kedar and deets , your return is INSIDE the for, so, in the first pixel it will return the value of countZero, instead of looping over all the image, just fixing the indention should be fine :

 for p in getPixels(newPict):
     r = getRed(p)
     b = getBlue(p)
     g = getGreen(p)
     if (r,g,b) == (0,0,0):
        countZero = countZero + 1
 return countZero