Python如何将图片转为字符

from PIL import Image
ascii_char=list('\~!@#.,[abcdefghij]wmnoxy$%;-=<>?:|^&*/ ')
def get_char(r,b,g,alpha=256):
    if alpha==0:
        return ' '
    gray=int(0.2126*r+0.7125*g+0.0722*b)
    uint=256/len(ascii_char)
    return ascii_char[int(gray/uint)]
def run():
    img=Image.open('0.jpg')
    WIDTH,HEIGHT=100,60
    img=img.resize((WIDTH,HEIGHT))
    txt=""
    for i in range(HEIGHT):
        for j in range(WIDTH):
            txt+=get_char(*img.getpixel((j,i)))
        txt+='\n'
    with open("pic.txt",'w') as fo:
        fo.write(txt)
    print(txt)    
run()