python文字ピクチャの生成

from PIL import Image
import argparse

#can shu chu li
parser = argparse.ArgumentParser()

parser.add_argument('file')
parser.add_argument('-o','--output')
parser.add_argument('--width',type = int ,default = 72)

parser.add_argument('--height',type = int, default = 40)

args = parser.parse_args()

IMG = args.file
WIDTH = args.width
HEIGHT = args.height
OUTPUT = args.output

ascii_char = list("$@B%8&WM#*oahkbdpqwmZO0QLCJUYXzcvunxrjft/\|()1{}[]?-_+~<>i!;:,\"^`'.")

def get_char(r,b,g,alpha = 256):
   if alpha == 0:
      return ' '
   length = len(ascii_char)
   gray = int(0.2126*r+0.7152*g+0.0722*b)

   unit = (256.0+1)/length
   return ascii_char[int(gray/unit)]

if __name__ == '__main__':
   im = Image.open(IMG)
   im = im.resize((WIDTH,HEIGHT),Image.NEAREST)

   txt = ""

   for i in range(HEIGHT):
      for j in range(WIDTH):
         txt += get_char(*im.getpixel((j,i)))
      txt += '
'

   print(txt)

   if OUTPUT:
      with open(OUTPUT,'w') as f:
         f.write(txt)
   else:
      with open("output.txt",'w') as f:
         f.write(txt)