On Tuesday, 25 September 2012 03:05:16 UTC+5:30, zipher wrote:
> For some time now, I've wanted to suggest a better abstraction for the
> type in Python. It currently uses an antiquated C-style interface for moving
> around in a file, with methods like tell() and seek(). But after attributes
Am 25.09.2012 09:28 schrieb Steven D'Aprano:
The whole concept is incomplete at one place: self.seek(10, 2) seeks
beyond EOF, potentially creating a sparse file. This is a thing you
cannot achieve.
On the contrary, since the pos attribute is just a wrapper around seek,
you can seek beyond EOF
On Wed, Sep 26, 2012 at 2:07 AM, Dennis Lee Bieber
wrote:
> f.pos += delta
>
> would be a "seek.set" and with a naive driver might trigger a rewind to
> the start of the tape followed by a seek to the absolute position,
> whereas the seek from current location would only move the tape by t
On 2012-09-25, Dennis Lee Bieber wrote:
> On Tue, 25 Sep 2012 08:22:05 +0200, Ulrich Eckhardt
> declaimed the following in
> gmane.comp.python.general:
>
>> Am 24.09.2012 23:49, schrieb Dave Angel:
>> > And what approach would you use for positioning relative to
>> > end-of-file? That's currently
Am 25.09.2012 10:13 schrieb Dennis Lee Bieber:
Or some bit setting registers, like on ATxmega: OUT = 0x10 sets bit 7
and clears all others, OUTSET = 0x10 only sets bit 7, OUTTGL = 0x10
toggles it and OUTCLR = 0x10 clears it.
Umpfzg. s/bit 7/bit 4/.
I don't think I'd want to work with
On 25 September 2012 11:51, Mark Lawrence wrote:
> On 25/09/2012 11:38, Oscar Benjamin wrote:
>
>> On 25 September 2012 08:27, Mark Lawrence
>> wrote:
>>
>> On 25/09/2012 03:32, Mark Adam wrote:
>>>
>>> On Mon, Sep 24, 2012 at 5:55 PM, Oscar Benjamin
wrote:
try:
> f.
On 25/09/2012 11:38, Oscar Benjamin wrote:
On 25 September 2012 08:27, Mark Lawrence wrote:
On 25/09/2012 03:32, Mark Adam wrote:
On Mon, Sep 24, 2012 at 5:55 PM, Oscar Benjamin
wrote:
try:
f.pos = 256
except IOError:
print('Unseekable file')
Something along these lines ht
On 25 September 2012 08:27, Mark Lawrence wrote:
> On 25/09/2012 03:32, Mark Adam wrote:
>
>> On Mon, Sep 24, 2012 at 5:55 PM, Oscar Benjamin
>> wrote:
>>
>>> try:
>>> f.pos = 256
>>> except IOError:
>>> print('Unseekable file')
>>
>>
> Something along these lines http://docs.python.or
On Sep 25, 2012 9:28 AM, "Dennis Lee Bieber" wrote:
>
> On Tue, 25 Sep 2012 08:22:05 +0200, Ulrich Eckhardt
> declaimed the following in
> gmane.comp.python.general:
>
> > Am 24.09.2012 23:49, schrieb Dave Angel:
> > > And what approach would you use for positioning relative to
> > > end-of-file?
On Mon, Sep 24, 2012 at 11:32 PM, Thomas Rachel
wrote:
> Am 25.09.2012 00:37 schrieb Ian Kelly:
>> Since ints are immutable, the language specifies that it should be the
>> equivalent of "file.pos = file.pos - 100", so it should set the file
>> pointer to 68 bytes before EOF.
>
>
> But this is not
On Tue, 25 Sep 2012 07:25:48 +0200, Thomas Rachel wrote:
> Am 25.09.2012 04:28 schrieb Steven D'Aprano:
>
>> By the way, the implementation of this is probably trivial in Python
>> 2.x. Untested:
>>
>> class MyFile(file):
>> @property
>> def pos(self):
>> return self.tell()
>>
On 25/09/2012 03:32, Mark Adam wrote:
On Mon, Sep 24, 2012 at 5:55 PM, Oscar Benjamin
wrote:
There are many situations where a little bit of attribute access magic is a
good thing. However, operations that involve the underlying OS and that are
prone to raising exceptions even in bug free code
Am 24.09.2012 23:49, schrieb Dave Angel:
And what approach would you use for positioning relative to
end-of-file? That's currently done with an optional second
> parameter to seek() method.
Negative indices.
;)
Uli
--
http://mail.python.org/mailman/listinfo/python-list
Am 25.09.2012 00:37 schrieb Ian Kelly:
On Mon, Sep 24, 2012 at 4:14 PM, Chris Angelico wrote:
file.pos = 42 # Okay, you're at position 42
file.pos -= 10 # That should put you at position 32
foo = file.pos # Presumably foo is the integer 32
file.pos -= 100 # What should this do?
Since ints are
Am 25.09.2012 04:28 schrieb Steven D'Aprano:
By the way, the implementation of this is probably trivial in Python 2.x.
Untested:
class MyFile(file):
@property
def pos(self):
return self.tell()
@pos.setter
def pos(self, p):
if p< 0:
self.seek(p
On Mon, Sep 24, 2012 at 5:55 PM, Oscar Benjamin
wrote:
> There are many situations where a little bit of attribute access magic is a
> good thing. However, operations that involve the underlying OS and that are
> prone to raising exceptions even in bug free code should not be performed
> implicitl
On Mon, 24 Sep 2012 15:36:20 -0700, zipher wrote:
> You raise a valid point: that by abstracting the file pointer into a
> position attribute you risk "de-coupling" the conceptual link between
> the underlying file and your abstraction in the python interpreter
I don't think this argument holds w
On Tue, 25 Sep 2012 08:14:01 +1000, Chris Angelico wrote:
> Presumably the same way you reference a list element relative to
> end-of-list: negative numbers. However, this starts to feel like magic
> rather than attribute assignment - it's like manipulating the DOM in
> JavaScript, you set an attr
On Mon, Sep 24, 2012 at 3:37 PM, Ian Kelly wrote:
> On Mon, Sep 24, 2012 at 4:14 PM, Chris Angelico wrote:
>> file.pos = 42 # Okay, you're at position 42
>> file.pos -= 10 # That should put you at position 32
>> foo = file.pos # Presumably foo is the integer 32
>> file.pos -= 100 # What should th
On 24/09/2012 22:35, zipher wrote:
For some time now, I've wanted to suggest a better abstraction for the
type in Python. It currently uses an antiquated C-style interface for moving around
in a file, with methods like tell() and seek(). But after attributes were introduced
to Python, it se
On Tue, Sep 25, 2012 at 8:37 AM, Ian Kelly wrote:
> On Mon, Sep 24, 2012 at 4:14 PM, Chris Angelico wrote:
>> file.pos = 42 # Okay, you're at position 42
>> file.pos -= 10 # That should put you at position 32
>> foo = file.pos # Presumably foo is the integer 32
>> file.pos -= 100 # What should th
On 24 September 2012 23:41, Mark Adam wrote:
> > seek() and tell() can raise exceptions on some files. Exposing pos as an
> > attribute and allowing it to be manipulated with attribute access gives
> the
> > impression that it is always meaningful to do so.
>
> It's a good point, python already
On Mon, Sep 24, 2012 at 4:14 PM, Chris Angelico wrote:
> file.pos = 42 # Okay, you're at position 42
> file.pos -= 10 # That should put you at position 32
> foo = file.pos # Presumably foo is the integer 32
> file.pos -= 100 # What should this do?
Since ints are immutable, the language specifies
(forwarding to the list)
On 09/24/2012 06:23 PM, Mark Adam wrote:
> On Mon, Sep 24, 2012 at 4:49 PM, Dave Angel wrote:
>> On 09/24/2012 05:35 PM, zipher wrote:
>>> For some time now, I've wanted to suggest a better abstraction for the
>>> type in Python. It currently uses an antiquated C-style
You raise a valid point: that by abstracting the file pointer into a position
attribute you risk "de-coupling" the conceptual link between the underlying
file and your abstraction in the python interpreter, but I think the programmer
can take responsibility for maintaining the abstraction.
Th
On Tue, Sep 25, 2012 at 7:49 AM, Dave Angel wrote:
> On 09/24/2012 05:35 PM, zipher wrote:
>> Let file-type have an attribute .pos for position. Now you can get rid of
>> the seek() and tell() methods and manipulate the file pointer more easily
>> with standard arithmetic operations.
>>
>
On Mon, Sep 24, 2012 at 2:49 PM, Dave Angel wrote:
>
> And what approach would you use for positioning relative to
> end-of-file? That's currently done with an optional second parameter to
> seek() method.
>
I'm not advocating for or against the idea, but that could be handled
the same way index
On 24 September 2012 22:35, zipher wrote:
> For some time now, I've wanted to suggest a better abstraction for the
> type in Python. It currently uses an antiquated C-style interface
> for moving around in a file, with methods like tell() and seek(). But
> after attributes were introduced to P
On 09/24/2012 05:35 PM, zipher wrote:
> For some time now, I've wanted to suggest a better abstraction for the
> type in Python. It currently uses an antiquated C-style interface for moving
> around in a file, with methods like tell() and seek(). But after attributes
> were introduced to Pyth
29 matches
Mail list logo
