On Sat, 03 Mar 2018 18:19:37 -0800, Ooomzay wrote:
>> def function():
>> x = open_resource()
>> process(x)
>> # and we're done with x now, but too lazy to explicitly close it
>> sleep(1) # Simulate some more work. Lots of work.
>> return
>> # and finally x is closed (2
On Sat, 03 Mar 2018 08:02:35 -0800, ooomzay wrote:
[...]
>> > But I am not! On the contrary RAII frees the programmer from even
>> > having to remember to close the file. The poster asked what would
>> > happen if the resource was deliberately kept open by storing a
>> > reference at global scope.
On Sun, Mar 4, 2018 at 1:45 PM, Ooomzay wrote:
> On Sunday, 4 March 2018 01:58:02 UTC, Gregory Ewing wrote:
>> ooomzay wrote:
>> > Well he was not telling you the whole story: RAII works just as well with
>> > heap objects using smart pointers (unique_ptr and friends) which are a
>> > closer
>>
On Sunday, 4 March 2018 01:58:02 UTC, Gregory Ewing wrote:
> ooomzay wrote:
> > Well he was not telling you the whole story: RAII works just as well with
> > heap objects using smart pointers (unique_ptr and friends) which are a
> > closer
> > analogy to python object references.
>
> By that def
On 3/3/18 9:10 PM, Chris Angelico wrote:
On Sun, Mar 4, 2018 at 1:01 PM, Ooomzay wrote:
On Saturday, 3 March 2018 17:44:08 UTC, Chris Angelico wrote:
On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon
Yes, stack allocated object in C++ have a nice lifetime to allow RAII to
work, but it doesn't j
Richard Damon wrote:
The
idea was to have a way to mark that certain classes/objects request that
they are reference counted so they get the __del__ called as soon as the
last reference goes away, without needing to require that overhead for
all objects in all implementations.
That could be
On Friday, 2 March 2018 15:37:25 UTC, Paul Moore wrote:
[snip]
> def fn():
> for i in range(1):
> with open(f"file{i}.txt", "w") as f:
> f.write("Some text")
>
> How would you write this in your RAII style - without leaving 10,000
> file descriptors op
Steven D'Aprano wrote:
Not just the class __dict__. You would have to do a full search of the
MRO looking for any superclass which defines such methods.
That could be reduced a lot by making it a type slot. But
it would still increase the overhead of every refcount change
by at least a factor o
On Saturday, 3 March 2018 23:52:34 UTC, Steven D'Aprano wrote:
> I know that laziness and hubris are programmer virtues, but there is
> still such a thing as *too much laziness*. RAII works in C++ where
> instances are allocated in the stack, but even there, if you have an
> especially long-liv
Paul Rubin wrote:
Richard Damon writes:
a class to define member functions like __ref__
and __unref__ (or perhaps some other name) that if defined, would be
called every time a name was bound or unbound to an object?
That sounds horrendous and wouldn't handle the case of a list element
creat
On Sun, Mar 4, 2018 at 1:01 PM, Ooomzay wrote:
> On Saturday, 3 March 2018 17:44:08 UTC, Chris Angelico wrote:
>> On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon
>> > Yes, stack allocated object in C++ have a nice lifetime to allow RAII to
>> > work, but it doesn't just work with stack allocated o
On Saturday, 3 March 2018 17:44:08 UTC, Chris Angelico wrote:
> On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon
> > Yes, stack allocated object in C++ have a nice lifetime to allow RAII to
> > work, but it doesn't just work with stack allocated objects. A lot of RAII
> > objects are members of a c
On Saturday, 3 March 2018 17:16:14 UTC, Ned Batchelder wrote:
> On 3/2/18 10:36 AM, Paul Moore wrote:
> > Or (real Python):
> >
> > def fn():
> > for i in range(1):
> > with open(f"file{i}.txt", "w") as f:
> > f.write("Some text")
> >
> > How would y
ooom...@gmail.com wrote:
Well he was not telling you the whole story: RAII works just as well with
heap objects using smart pointers (unique_ptr and friends) which are a closer
analogy to python object references.
By that definition, *all* resource management in Python is
based on RAII[1]. The
On Friday, March 2, 2018 at 5:29:54 AM UTC, Rustom Mody wrote:
> Please excuse if this has been addressed above and/or its too basic:
> What's the difference between RAII and python's with/context-managers?
They address the same problem but I am claiming that RAII achieves this in a
significantly
On Friday, March 2, 2018 at 3:37:25 PM UTC, Paul Moore wrote:
> [...]
> RAII works in C++ (where it was initially invented) because it's used
> with stack-allocated variables that have clearly-defined and limited
> scope.
RAII also works with smart pointers, which are a closer analogue
to pyth
On 3/3/18 6:57 PM, Steven D'Aprano wrote:
On Sat, 03 Mar 2018 10:01:43 -0700, Ian Kelly wrote:
On Sat, Mar 3, 2018 at 9:19 AM, Richard Damon
wrote:
One idea does come to mind though, would it be reasonable, and somewhat
Pythonic, for a class to define member functions like __ref__ and
__unref
On 3/3/18 6:49 PM, Steven D'Aprano wrote:
On Sat, 03 Mar 2018 12:37:08 -0500, Richard Damon wrote:
With RAII and immediate destruction on end of scope, we can automate the
release, without it and you need a lot of explicit code to manage these
resources.
Not so much.
with resource_i_care_abou
On Sat, 03 Mar 2018 10:01:43 -0700, Ian Kelly wrote:
> On Sat, Mar 3, 2018 at 9:19 AM, Richard Damon
> wrote:
>> One idea does come to mind though, would it be reasonable, and somewhat
>> Pythonic, for a class to define member functions like __ref__ and
>> __unref__ (or perhaps some other name) t
On Sat, 03 Mar 2018 12:37:08 -0500, Richard Damon wrote:
> With RAII and immediate destruction on end of scope, we can automate the
> release, without it and you need a lot of explicit code to manage these
> resources.
Not so much.
with resource_i_care_about() as rsrc:
process(rsrc)
is har
On Sat, Mar 3, 2018 at 3:26 PM, Richard Damon wrote:
> On 2/28/18 3:51 PM, Ian Kelly wrote:
>>
>> On Wed, Feb 28, 2018 at 12:55 PM, wrote:
>>>
>>> On Tuesday, 27 February 2018 00:42:02 UTC+1, Paul Rubin wrote:
Ron Aaron posted the below url on comp.lang.forth. It points to what I
>>>
On Saturday, March 3, 2018 at 4:33:59 PM UTC, Michael Torrie wrote:
> On 03/03/2018 09:02 AM, ooomzay wrote:
> > I can assure you that RAII does what it says on the tin and is relied on in
> > many critical systems to release resources robustly ... given the
> > pre-requisite deterministic destru
On 2/28/18 3:51 PM, Ian Kelly wrote:
On Wed, Feb 28, 2018 at 12:55 PM, wrote:
On Tuesday, 27 February 2018 00:42:02 UTC+1, Paul Rubin wrote:
Ron Aaron posted the below url on comp.lang.forth. It points to what I
thought was a cute problem, along with his solution in his Forth dialect
8th:
On 3/3/18 1:28 PM, Chris Angelico wrote:
On Sun, Mar 4, 2018 at 5:22 AM, Richard Damon wrote:
On 3/3/18 12:43 PM, Chris Angelico wrote:
On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon
wrote:
On 3/3/18 11:33 AM, Michael Torrie wrote:
On 03/03/2018 09:02 AM, ooom...@gmail.com wrote:
I can assu
Hello!
I'm pleased to announce version 3.1.0, the first stable release of branch
3.1 of CheetahTemplate3.
What's new in CheetahTemplate3
==
Contributors for this release is Mathias Stearn.
Features:
- Fix Cheetah to work with PyPy. Pull request by Mathias Stearn.
On Sun, Mar 4, 2018 at 5:22 AM, Richard Damon wrote:
> On 3/3/18 12:43 PM, Chris Angelico wrote:
>>
>> On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon
>> wrote:
>>>
>>> On 3/3/18 11:33 AM, Michael Torrie wrote:
On 03/03/2018 09:02 AM, ooom...@gmail.com wrote:
>
> I can assure you
On 3/3/18 12:43 PM, Chris Angelico wrote:
On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon wrote:
On 3/3/18 11:33 AM, Michael Torrie wrote:
On 03/03/2018 09:02 AM, ooom...@gmail.com wrote:
I can assure you that RAII does what it says on the tin and is relied on
in
many critical systems to releas
On Sun, Mar 4, 2018 at 4:37 AM, Richard Damon wrote:
> On 3/3/18 11:33 AM, Michael Torrie wrote:
>>
>> On 03/03/2018 09:02 AM, ooom...@gmail.com wrote:
>>>
>>> I can assure you that RAII does what it says on the tin and is relied on
>>> in
>>> many critical systems to release resources robustly ..
On 3/3/18 11:33 AM, Michael Torrie wrote:
On 03/03/2018 09:02 AM, ooom...@gmail.com wrote:
I can assure you that RAII does what it says on the tin and is relied on in
many critical systems to release resources robustly ... given the
pre-requisite deterministic destruction.
Sure but did you read
On Sun, Mar 4, 2018 at 3:19 AM, Richard Damon wrote:
> One idea does come to mind though, would it be reasonable, and somewhat
> Pythonic, for a class to define member functions like __ref__ and __unref__
> (or perhaps some other name) that if defined, would be called every time a
> name was bound
On 2/28/18 6:53 PM, ooom...@gmail.com wrote:
On Wednesday, February 28, 2018 at 11:45:24 PM UTC, ooo...@gmail.com wrote:
On Wednesday, February 28, 2018 at 11:02:17 PM UTC, Chris Angelico wrote:
On Thu, Mar 1, 2018 at 9:51 AM, ooomzay wrote:
[snip]
Taking a really simple situation:
class Foo:
On 3/2/18 10:36 AM, Paul Moore wrote:
Or (real Python):
def fn():
for i in range(1):
with open(f"file{i}.txt", "w") as f:
f.write("Some text")
How would you write this in your RAII style - without leaving 10,000
file descriptors open until the end
On 2/28/2018 11:51 PM, ooom...@gmail.com wrote:
This PEP proposes that valid python interpreters *must* synchronously destroy
objects when the last reference to an object goes out of scope. This
interpreter behaviour is currently permitted and exhibited by the reference
implementation [CPython
On Sun, Mar 4, 2018 at 3:19 AM, Richard Damon wrote:
> On 3/3/18 9:03 AM, Ian Kelly wrote:
>>
>> On Fri, Mar 2, 2018 at 9:57 PM, Gregory Ewing
>> wrote:
>>>
>>> Paul Rubin wrote:
So you want the programmer to put more head scratching into figuring out
which reference should be stro
On Sat, Mar 3, 2018 at 9:19 AM, Richard Damon wrote:
> One idea does come to mind though, would it be reasonable, and somewhat
> Pythonic, for a class to define member functions like __ref__ and __unref__
> (or perhaps some other name) that if defined, would be called every time a
> name was bound
On 03/03/2018 09:02 AM, ooom...@gmail.com wrote:
> I can assure you that RAII does what it says on the tin and is relied on in
> many critical systems to release resources robustly ... given the
> pre-requisite deterministic destruction.
Sure but did you read what Paul Moore wrote? He said RAI
On 3/3/18 9:03 AM, Ian Kelly wrote:
On Fri, Mar 2, 2018 at 9:57 PM, Gregory Ewing
wrote:
Paul Rubin wrote:
So you want the programmer to put more head scratching into figuring out
which reference should be strong and which should be weak?
Also, sometimes weak references don't really solve th
On Friday, March 2, 2018 at 10:43:57 PM UTC, Steven D'Aprano wrote:
> On Fri, 02 Mar 2018 07:09:19 -0800, ooomzay wrote:
> [...]
> >> If you're going to *require* the programmer to explicitly del the
> >> reference:
> >>
> >> f = open("file")
> >> text = f.read()
> >> del f
> >
> > But
Hello,
I found a difference of behavior about `except` statement between CPython
2.7 and 3.x .
`except EXC_CLASS:` calls `__subclasscheck__` in 2.7, but does not in 3.x .
Let me show you an example.
Now, define a class "ExceptionLike" (with metaclass "ExceptionLikeMeta")
below.
class ExceptionL
On Fri, Mar 2, 2018 at 9:57 PM, Gregory Ewing
wrote:
> Paul Rubin wrote:
>>
>> So you want the programmer to put more head scratching into figuring out
>> which reference should be strong and which should be weak?
>
>
> Also, sometimes weak references don't really solve the
> problem, e.g. if you
after a few tests, it appears that the file is read in pieces:
read[0] 131072 bytes from 0 flags: 0x8000
read[0] 131072 bytes from 131072 flags: 0x8000
read[0] 131072 bytes from 262144 flags: 0x8000
...
read[0] 8192 bytes from 917504 flags: 0x8000
read[0] 4096 bytes from 925696 flags: 0x8000
so t
hello,
my xb360hd module allows me to browse a xtaf partition (xbox360) and extract
files.
a file can be large (and discontinuous), so the readFile function of the module
returns a generator.
from a console, I can "easily" copy a file with this piece of code:
partition = xb360hd.Xtaf('/dev/sd
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