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From: kent nyberg <kent@z-sverige.nu>
Newsgroups: comp.lang.python
Subject: Re: Problems using struct pack/unpack in files, and reading them.
Date: Fri, 13 Nov 2015 16:34:50 -0500
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Xref: csiph.com comp.lang.python:98772

The main problem was that I forgot to do seek(0).  Thanks alot people.

Though, as many times before, the problem was due to misunderstanding of how python works.
I assumed file.read()[xx:yy] was to be understood as,   in the file, read from index xx to place yy.
That is,  [10:20]  was the same as,   read from 10th char to 20th.  Sort of.


Is it true then to say that every .read  of a file, places an index-offset (?) from where the next read starts?
That is, I need to rewind the file, or else the read will start from where the last read stopped?