gistfile1.py

#!/opt/local/bin/python
# -*- coding: utf-8 -*-

import os
import urllib
import re


SAVE_DIR = '/tmp/foobar'

p = re.compile('http://gyazo.com.*.png')

i = 0
for line in open('/tmp/log.txt'):
    m = p.search(line)
    if m != None:
        url = line[m.start():m.end()]
        print(url)
        urllib.urlretrieve(url, SAVE_DIR + os.path.split(url)[1])