sha1,256,512 on files

[durumdara at mailpont.hu]

Hi !

I have a problem in Windows.
I need to get the filelist in HDD-s, with sha-N value for every file (to 
see what changed in the past).

1.
I see that Python supports the sha-1. But I need to make sha value in 
big files to (swap file, iso-s, etc.). Possible that file size more than 
2 GB, so  I cannot read as string...
How to get the sha value of a file ?
If python not supports that, please give me a link with  freeware 
command line utility that can do it,and can pass to python.

2.
How to generate sha-256, or sha-512 values ?

Thanx for every help: dd