[SciPy-user] Manipulating Bit-Masked Data
dkuhlman at cutter.rexx.com
Tue Dec 27 22:18:19 CST 2005
On Tue, Dec 27, 2005 at 04:55:47PM -0800, Rich Shepard wrote:
> I need to read bit-masked bytes from an Optical Mark Recognition card
> reader. I'm quite new to Python and haven't found any documentation on how to
> manipulate bits. NumPy has masked arrays, but that's a different situation.
> My rummaging around the SciPy wiki and a search of the mail list archives
> turned up nothing.
> I'd appreciate a pointer to documentation that will show me how to
> manipulate bit-masks in Python.
Define your hex masks with things like 0x1f. See:
And, I believe, the bit-wise operators you want are "&", "^", and
"|" (and, xor, and or). See:
Also, the built-in functions ord() and hex() may be useful. See:
If you need lots of speed while doing this, you may want to look into
Pyrex. But, that's an advanced topic.
Hope this helps.
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