Robin Becker wrote:
>> Does anyone know of a fast way to calculate checksums for a large file. I
>> need a way to generate
>> ETag keys for a webserver, the ETag of large files are not realy nececary,
>> but it would be nice
>> if I could do it. I'm using the python hash function on the dynamic
>> generated strings (like in
>> page content) but on things like images I use the shutil's copyfileobject
>> function and the hash
>> of a fileobject's hash are it's handlers memmory address.
>>
>> Does anyone know a python utility which is possible to use, perhaps
>> something like the md5sum
>> utility on *nix systems.
>>
> well md5sum is usable on many systems. I run it on win32 and darwin.
>
> I tried this in 2.4 with the new subprocess module
on my machine, Python's md5+mmap is a little bit faster than
subprocess+md5sum:
import os, md5, mmap
file = open(fn, "r+")
size = os.path.getsize(fn)
hash = md5.md5(mmap.mmap(file.fileno(), size)).hexdigest()
(I suspect that md5sum also uses mmap, so the difference is
probably just the subprocess overhead)
</F>
--
http://mail.python.org/mailman/listinfo/python-list
