Marc-Andre Lemburg wrote:
>Regarding the issue itself: I think this is a wrong interpretation of
>what the buffering parameter does. File buffering is different
>from .readline() buffering (which can be customized on a per-call
>basis by specifying a size parameter).

Ok. But builtin's readline buffering works like (I) expected. So there is a difference in behavior between builtins readline an codecs.readline (and it bite me). ¿Maybe it should be noted in documentation?

Python 3.2a3+ (py3k, Nov  6 2010, 16:17:14)
[GCC 4.5.1] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> f = open("foo.txt", "rb", buffering=0)
>>> f.readline()
b'bar\n'
>>> f.tell()
4