CAPTCHA, caso especial: rompemos una red neuronal con treinta líneas de código

from PIL import Image, ImageTk

def recognize(filepath):
  Zlist = [] # [(x1, z1), (x2, z2), (x3, z3), etc.] - position and digit
  captcha = ""
  originalimage = Image.open(filepath).convert('L').point(lambda x : 255 if x > 20 else 0, mode='1').convert('1').convert('RGBA')
  if originalimage.getextrema() == ((0, 0), (0, 0), (0, 0), (255, 255)):
    return("empty image")
  for z in [4, 2, 3, 1, 5, 6, 7, 8, 9]: # reorder to exclude false 1 on 4
    mask = Image.open('mask' + str(z) + '.png').convert('RGBA')
    previ = 0
    for i in range(15, 120): # no digit in left part
      resultimage = Image.alpha_composite(originalimage.crop((i, 0, i + 30, 0 + 50)), mask)
      if resultimage.getextrema() == ((0, 0), (0, 0), (0, 0), (255, 255)):
        if z == 4: # delete 4 to exclude false 1 on 4
          maskx = Image.open('mask4x.png').convert('RGBA') 
          originalimage.paste(Image.alpha_composite(originalimage.crop((i, 0, i + 30, 0 + 50)), maskx), (i, 0))
        if previ == 0 or i > previ + 15: #no digit closer then 15 px
          Zlist.append((i, z))
          if len(Zlist) == 5:
              Zlist.sort()
              for z in Zlist:
                captcha = captcha + str(z[1])
              return(captcha)
          previ = i
          i = i + 15 #skip a little
  Zlist.sort()
  return(str(Zlist)) #if less then 5 digits recognized
	
def main():
  captcha = recognize(entry.path)
#----------------------------------------------#
#          #
#----------------------------------------------#

main()