python snippet request: calculate MD5 checksum on 650 MB ISO cdrom image quickly
Oleg Broytmann
phd at phd.russ.ru
Wed Oct 25 04:21:13 EDT 2000
On Tue, 24 Oct 2000, Warren Postma wrote:
> A new function in the md5 module, md5.md5file(filename) would be nice, if
> anyone is listening, for a future python 2.x release.
----- md5wrapper.py -----
#! /usr/local/bin/python
"""
User wrapper for md5 builtin object
Written by BroytMann, Jun 1997. Copyright (C) 1997 PhiloSoft Design
"""
from md5 import md5
class md5wrapper:
def __init__(self, init=None):
if init:
self._md5 = md5(init)
else:
self._md5 = md5()
def update(self, data):
self._md5.update(data)
def digest(self):
return self._md5.digest()
def __repr__(self):
str = self.digest()
return "%02x"*len(str) % tuple(map(ord, str))
# This nice was suggested by Guido
def md5file(self, f):
if type(f) == type(''): # If f is string - use it as file's name
infile = open(f, 'r')
else:
infile = f # else assume it is opened file (fileobject) or
# "compatible" object (must has readline() method)
try:
while 1:
buf = infile.read(16*1024)
if not buf: break
self.update(buf)
finally:
if type(f) == type(''): # If f was opened - close it
infile.close()
if __name__ == "__main__":
print "This must print exactly the string"
print "Test: 900150983cd24fb0d6963f7d28e17f72"
print "Test:", md5wrapper("abc")
----- /md5wrapper.py -----
Oleg. (All opinions are mine and not of my employer)
----
Oleg Broytmann Foundation for Effective Policies phd at phd.russ.ru
Programmers don't die, they just GOSUB without RETURN.
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