equivalent in javascript:

{a, b, ...rest} = {a: 1, b: 2, c: 3, d: 4}

Not a bad replacement for that! I still find javascript's syntax a little more easily readable and natural, but given that we can't use the same syntax (probably because it would be incompatible with existing syntax rules that we can't break for compatibility reasons, unfortunately), this is a pretty good compromise/solution that they've come up with.

具体实现：

#!/usr/bin/python

import glob
import os
import sys

from PIL import Image

EXTS = 'jpg', 'jpeg', 'JPG', 'JPEG', 'gif', 'GIF', 'png', 'PNG'

def avhash(im):
    if not isinstance(im, Image.Image):
        im = Image.open(im)
    im = im.resize((8, 8), Image.ANTIALIAS).convert('L')
    avg = reduce(lambda x, y: x + y, im.getdata()) / 64.
    return reduce(lambda x, (y, z): x | (z << y),
                  enumerate(map(lambda i: 0 if i < avg else 1, im.getdata())),
                  0)

def hamming(h1, h2):
    h, d = 0, h1 ^ h2
    while d:
        h += 1
        d &= d - 1
    return h

if __name__ == '__main__':
    if len(sys.argv) <= 1 or len(sys.argv) > 3:
        print "Usage: %s image.jpg [dir]" % sys.argv[0]
    else:
        im, wd = sys.argv[1], '.' if len(sys.argv) < 3 else sys.argv[2]
        h = avhash(im)

        os.chdir(wd)
        images = []
        for ext in EXTS:
            images.extend(glob.glob('*.%s' % ext))

        seq = []
        prog = int(len(images) > 50 and sys.stdout.isatty())
        for f in images:
            seq.append((f, hamming(avhash(f), h)))
            if prog:
                perc = 100. * prog / len(images)
                x = int(2 * perc / 5)
                print '\rCalculating... [' + '#' * x + ' ' * (40 - x) + ']',
                print '%.2f%%' % perc, '(%d/%d)' % (prog, len(images)),
                sys.stdout.flush()
                prog += 1

        if prog: print
        for f, ham in sorted(seq, key=lambda i: i[1]):
            print "%d\t%s" % (ham, f)

参考代码：

1. http://www.ruanyifeng.com/blog/2011/07/imgHash.txt