Ola Natvig 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.
Is there a reason you can't use the sha module? Using a random large file I
had
lying around:
sha.new(file("jdk-1_5_0-linux-i586.rpm").read()).hexdigest() # loads all into
memory first
If you don't want to load the whole object into memory at once you can always
call out to the sha1sum utility yourself as well.
>>> subprocess.Popen(["sha1sum", ".bashrc"],
stdout=subprocess.PIPE).communicate()[0].split()[0]
'5c59906733bf780c446ea290646709a14750eaad'
--
Michael Hoffman
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