[Python-Dev] bitwise operations for bytes and bytearray (original) (raw)

Brett Cannon brett at python.org
Thu Jan 7 17:38:29 EST 2016

On Thu, 7 Jan 2016 at 14:29 Blake Griffith <blake.a.griffith at gmail.com> wrote:

Hi!

I'm interested in adding the functionality to do something like: >>> b'a' ^ b'b' b'\x03'

Instead of the good ol' TypeError. I think both bytes and bytearray should support all the bitwise operations. I've never hacked on cpython before. I'm starting by just trying to add xor to bytearray. I have a ByteArrayXor function that I think should do this here https://github.com/cowlicks/cpython/commit/d6dddb11cdb33032b39dcb9dfdaa7b10d4377b5f But I'm not sure how to hook this in to the rest of cypython. I tried adding it where bytearrayassequence is declared in this bytearrayobject.c file. But that gave me compiler warnings and broke things. So now that I have this ByteArrayXor function, how do I make it be bytearray.xor?

You need to set the PyNumberMethods struct with the appropriate function and then set that on the PyTypeObject. Look at https://hg.python.org/cpython/file/tip/Include/object.h#l237 and https://hg.python.org/cpython/file/tip/Objects/longobject.c#l5238 for an idea of what it takes. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://mail.python.org/pipermail/python-dev/attachments/20160107/92a37da2/attachment.html>

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