Python実現md 5

'''
    md5sum in Python

ex:
    import hashlib
    m = hashlib.md5('stunnel-4.48.tar.gz')
    m.digest()
    print m.hexdigest()
'''

try:
  from hashlib import md5        #Python2.5 or later version
except:
  from md5 import md5            #Python2.4 or before version

import sys
import urllib

def sumfile(fobj):
  m = md5()
  while True:
    d = fobj.read()
    if not d:
      break
    m.update(d)
    del(d)
  return m.hexdigest()

def sumstr(str):
  m = md5()
  m.update(str)
  return m.hexdigest()

def md5sum(fname):     
  try:
    f = urllib.urlopen(fname, 'rb')
    #f = open(fname, 'rb')
  except:
    return False
  ret = sumfile(f)
  f.close()  
  return ret

res=md5sum('http://stunnel.cybermirror.org/stunnel-4.48.tar.gz')
print res