[Python-Dev] new buffer in python2.7 (original) (raw)

Lennart Regebro regebro at gmail.com
Mon Nov 8 12:08:24 CET 2010

On Wed, Oct 27, 2010 at 12:36, Antoine Pitrou <solipsis at pitrou.net> wrote:

On Wed, 27 Oct 2010 10:13:12 +0800 Kristján Valur Jónsson <kristjan at ccpgames.com> wrote:

Although 2.7 has the new buffer interface and memoryview objects, these are widely not accepted in the built in modules. That's true, and slightly unfortunate. It could be a reason for switching to 3.1/3.2 :-)

It's rather a reason against it, as it makes supporting both Python 2 and Python 3 harder. However, fixing this in 2.7 just means that you need to support 2.7x or later only, so it's not a good solution. I think using compatibility types is a better solution. I suggested something like that for inclusion in "six", but it was softly rejected. :-)

Something like this, for example. It's a str in Python2 and a Bytes in Python3, but it extends both classes with a consistent interface. Improvements, comments and ideas are welcome.

bites.py:

import sys if sys.version < '3': class Bites(str): def new(cls, value): if isinstance(value[0], int): # It's a list of integers value = ''.join([chr(x) for x in value]) return super(Bites, cls).new(cls, value)

    def itemint(self, index):
        return ord(self[index])

    def iterint(self):
        for x in self:
            yield ord(x)

else:

class Bites(bytes):
    def __new__(cls, value):
        if isinstance(value, str):
            # It's a unicode string:
            value = value.encode('ISO-8859-1')
        return super(Bites, cls).__new__(cls, value)

    def itemint(self, x):
        return self[x]

    def iterint(self):
        for x in self:
            yield x

-- Lennart Regebro: http://regebro.wordpress.com/ Python 3 Porting: http://python3porting.com/ +33 661 58 14 64

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