Problem reading/writing files

[smeenehan at hmc.edu]

This is a bit of a peculiar problem. First off, this relates to Python
Challenge #12, so if you are attempting those and have yet to finish
#12, as there are potential spoilers here.

I have five different image files shuffled up in one big binary file.
In order to view them I have to "unshuffle" the data, which means
moving bytes around. Currently my approach is to read the data from the
original, unshuffle as necessary, and then write to 5 different files
(2 .jpgs, 2 .pngs and 1 .gif).

The problem is with the read() method. If I read a byte valued as 0x00
(in hexadecimal), the read method returns a character with the value
0x20. When printed as strings, these two values look the same (null and
space, respectively), but obviously this screws with the data and makes
the resulting image file unreadable. I can add a simple if statement to
correct this, which seems to make the .jpgs readable, but the .pngs
still have errors and the .gif is corrupted, which makes me wonder if
the read method is not doing this to other bytes as well.

Now, the *really* peculiar thing is that I made a simple little file
and used my hex editor to manually change the first byte to 0x00. When
I read that byte with the read() method, it returned the correct value,
which boggles me.

Anyone have any idea what could be going on? Alternatively, is there a
better way to shift about bytes in a non-text file without using the
read() method (since returning the byte as a string seems to be what's
causing the issue)? Thanks in advance!