From akitada at gmail.com  Thu Nov  6 00:30:05 2008
From: akitada at gmail.com (Akira Kitada)
Date: Thu, 6 Nov 2008 08:30:05 +0900
Subject: [capi-sig] Fwd: Can I build Python with lthread instead of pthread?
In-Reply-To: <gesge2$738$1@panix3.panix.com>
References: <mailman.3365.1225472233.3487.python-list@python.org>
	<gesge2$738$1@panix3.panix.com>
Message-ID: <90bb445a0811051530v2a00c747u5ec538c85c24258c@mail.gmail.com>

suggested to try to ask capi-sig for this question.
Forwarding.


---------- Forwarded message ----------
From: Aahz <aahz at pythoncraft.com>
Date: Thu, Nov 6, 2008 at 1:08 AM
Subject: Re: Can I build Python with lthread instead of pthread?
To: python-list at python.org


In article <mailman.3365.1225472233.3487.python-list at python.org>,
Akira Kitada <akitada at gmail.com> wrote:
>
>I'm running Python 2.5 on FreeBSD 4.
>pthread on FreeBSD 4 has some problems so I would like to build
>python with lthread (linuxthreads) instead of BSD's pthread.
>So I looked at configure options but couldn't find any options for it.
>Python support lthread? and how can I build python with it?

You may want to try asking on capi-sig
--
Aahz (aahz at pythoncraft.com)           <*>         http://www.pythoncraft.com/

import antigravity
--
http://mail.python.org/mailman/listinfo/python-list

From philipp at achtziger.de  Tue Nov 11 15:55:58 2008
From: philipp at achtziger.de (Philipp Heuser)
Date: Tue, 11 Nov 2008 15:55:58 +0100
Subject: [capi-sig] Beginner Question PyObject* to int
Message-ID: <49199CFE.20608@achtziger.de>

Hi all,

I am just starting to use the C API for Python. What I want to do is to 
use an external funtion availabele in C and therfore I want to 'convert' 
a list of floats from Python to an array of floats in C which I can 
forward to the external function. So first step is tp parse a list to C 
and let the C code print the variables! The obviously too simplistic 
approach is below... When I call this function from python, e.g. 
cpp([1,2,3]) the output is:
25180552
25180540
25180528

Could you be so kind to help me here to get started with using 
C-functions from Python? Where is the error?

Thank you very much and kind regards,

Philipp



static PyObject *
cpp_foo(PyObject *self, PyObject* args)
{
    
    PyObject* obj;
    PyObject* seq;
    
    int i, len;
    
    if(!PyArg_ParseTuple(args, "O", &obj))
        return NULL;
        
    seq = PySequence_Fast(obj, "expected a sequence");
    len = PySequence_Size(obj);
    
    PyObject* item;
    int a;

    for (i=0; i<len; i++)
    {
        item=PySequence_Fast_GET_ITEM(seq, i);
        a=item;  // ?????????????????????????????????????????
        printf("%i\n", a);
    }
    
    Py_DECREF(seq);    
    return None;
}


From miles.chris at gmail.com  Wed Nov 12 13:05:28 2008
From: miles.chris at gmail.com (Chris Miles)
Date: Wed, 12 Nov 2008 23:05:28 +1100
Subject: [capi-sig] Beginner Question PyObject* to int
In-Reply-To: <49199CFE.20608@achtziger.de>
References: <49199CFE.20608@achtziger.de>
Message-ID: <E2942E6E-66A4-4A2D-AFCA-3E59F3AB53F5@gmail.com>


On 12/11/2008, at 1:55 AM, Philipp Heuser wrote:

> Hi all,
>
> I am just starting to use the C API for Python. What I want to do is  
> to use an external funtion availabele in C and therfore I want to  
> 'convert' a list of floats from Python to an array of floats in C  
> which I can forward to the external function. So first step is tp  
> parse a list to C and let the C code print the variables! The  
> obviously too simplistic approach is below... When I call this  
> function from python, e.g. cpp([1,2,3]) the output is:
> 25180552
> 25180540
> 25180528
>
> Could you be so kind to help me here to get started with using C- 
> functions from Python? Where is the error?
>
> Thank you very much and kind regards,
>
> Philipp
>
>
>
> static PyObject *
> cpp_foo(PyObject *self, PyObject* args)
> {
>      PyObject* obj;
>   PyObject* seq;
>      int i, len;
>      if(!PyArg_ParseTuple(args, "O", &obj))
>       return NULL;
>          seq = PySequence_Fast(obj, "expected a sequence");
>   len = PySequence_Size(obj);
>      PyObject* item;
>   int a;
>
>   for (i=0; i<len; i++)
>   {
>       item=PySequence_Fast_GET_ITEM(seq, i);
>       a=item;  // ?????????????????????????????????????????

Perhaps something like:

     long a;
     a = PyInt_AsLong(item);
     if (a == -1 && PyErr_Occurred())
         return NULL; /* error */
     printf("%i\n", a);

Cheers,
Chris Miles


From ggpolo at gmail.com  Wed Nov 12 13:06:27 2008
From: ggpolo at gmail.com (Guilherme Polo)
Date: Wed, 12 Nov 2008 10:06:27 -0200
Subject: [capi-sig] Beginner Question PyObject* to int
In-Reply-To: <49199CFE.20608@achtziger.de>
References: <49199CFE.20608@achtziger.de>
Message-ID: <ac2200130811120406r7ec66da2n43044168d5e1f604@mail.gmail.com>

On Tue, Nov 11, 2008 at 12:55 PM, Philipp Heuser <philipp at achtziger.de> wrote:
> Hi all,
>
> I am just starting to use the C API for Python. What I want to do is to use
> an external funtion availabele in C and therfore I want to 'convert' a list
> of floats from Python to an array of floats in C which I can forward to the
> external function. So first step is tp parse a list to C and let the C code
> print the variables! The obviously too simplistic approach is below... When
> I call this function from python, e.g. cpp([1,2,3]) the output is:
> 25180552
> 25180540
> 25180528
>
> Could you be so kind to help me here to get started with using C-functions
> from Python? Where is the error?
>
> Thank you very much and kind regards,
>
> Philipp
>
>
>
> static PyObject *
> cpp_foo(PyObject *self, PyObject* args)
> {
>     PyObject* obj;
>   PyObject* seq;
>     int i, len;
>     if(!PyArg_ParseTuple(args, "O", &obj))
>       return NULL;
>         seq = PySequence_Fast(obj, "expected a sequence");
>   len = PySequence_Size(obj);
>     PyObject* item;
>   int a;
>
>   for (i=0; i<len; i++)
>   {
>       item=PySequence_Fast_GET_ITEM(seq, i);
>       a=item;  // ?????????????????????????????????????????

Add more '?'s here.
PySequence_FAST_GET_ITEM returns a PyObject, you can't just go and
give it to 'a' to turn it into an integer. Also, this variable 'i'
better be of type Py_ssize_t instead of int.

So, to get your value as a long, first check item is indeed a long
using PyLong_Check(item) and then convert it to a long with
PyLong_AsLong(item):

>       printf("%i\n", a);
>   }
>     Py_DECREF(seq);       return None;
> }
>
> _______________________________________________
> capi-sig mailing list
> capi-sig at python.org
> http://mail.python.org/mailman/listinfo/capi-sig
>



-- 
-- Guilherme H. Polo Goncalves

From philipp at achtziger.de  Wed Nov 12 14:37:05 2008
From: philipp at achtziger.de (Philipp Heuser)
Date: Wed, 12 Nov 2008 14:37:05 +0100
Subject: [capi-sig] Beginner Question PyObject* to int
In-Reply-To: <E2942E6E-66A4-4A2D-AFCA-3E59F3AB53F5@gmail.com>
References: <49199CFE.20608@achtziger.de>
	<E2942E6E-66A4-4A2D-AFCA-3E59F3AB53F5@gmail.com>
Message-ID: <491ADC01.1080809@achtziger.de>

Thanks for your replies!

Philipp

From stefan_ml at behnel.de  Wed Nov 12 12:55:00 2008
From: stefan_ml at behnel.de (Stefan Behnel)
Date: Wed, 12 Nov 2008 12:55:00 +0100 (CET)
Subject: [capi-sig] Beginner Question PyObject* to int
In-Reply-To: <49199CFE.20608@achtziger.de>
References: <49199CFE.20608@achtziger.de>
Message-ID: <54669.213.61.181.86.1226490900.squirrel@groupware.dvs.informatik.tu-darmstadt.de>

Philipp Heuser wrote:
> I am just starting to use the C API for Python. What I want to do is to
> use an external funtion availabele in C and therfore I want to 'convert'
> a list of floats from Python to an array of floats in C

Since you're just starting, it's generally worth looking into Cython
first, before investing time to learn the raw Python C-API.

http://cython.org/

Stefan


From koder.mail at gmail.com  Thu Nov 13 13:00:36 2008
From: koder.mail at gmail.com (KoDer)
Date: Thu, 13 Nov 2008 14:00:36 +0200
Subject: [capi-sig] Beginner Question PyObject* to int
In-Reply-To: <54669.213.61.181.86.1226490900.squirrel@groupware.dvs.informatik.tu-darmstadt.de>
References: <49199CFE.20608@achtziger.de>
	<54669.213.61.181.86.1226490900.squirrel@groupware.dvs.informatik.tu-darmstadt.de>
Message-ID: <6e8b06c90811130400m5bfcf9dfo20508fad7e3854a7@mail.gmail.com>

2008/11/12 Stefan Behnel <stefan_ml at behnel.de>:
> Philipp Heuser wrote:
>> I am just starting to use the C API for Python. What I want to do is to
>> use an external funtion availabele in C and therfore I want to 'convert'
>> a list of floats from Python to an array of floats in C
>
> Since you're just starting, it's generally worth looking into Cython
> first, before investing time to learn the raw Python C-API.
>
> http://cython.org/
>

Or http://cxx.sourceforge.net/

-- 
K.Danilov aka KoDer
ICQ:214286120
Skype:koder.ua
Tel:8-050-4030512
Jabber:koder_ua at jabber.ru

From python_capi at behnel.de  Thu Nov 13 13:45:28 2008
From: python_capi at behnel.de (Stefan Behnel)
Date: Thu, 13 Nov 2008 13:45:28 +0100 (CET)
Subject: [capi-sig] Beginner Question PyObject* to int
In-Reply-To: <6e8b06c90811130400m5bfcf9dfo20508fad7e3854a7@mail.gmail.com>
References: <49199CFE.20608@achtziger.de>
	<54669.213.61.181.86.1226490900.squirrel@groupware.dvs.informatik.tu-darmstadt.de>
	<6e8b06c90811130400m5bfcf9dfo20508fad7e3854a7@mail.gmail.com>
Message-ID: <65384.213.61.181.86.1226580328.squirrel@groupware.dvs.informatik.tu-darmstadt.de>

KoDer wrote:
> 2008/11/12 Stefan Behnel:
>> Since you're just starting, it's generally worth looking into Cython
>> first, before investing time to learn the raw Python C-API.
>>
>> http://cython.org/
>
> Or http://cxx.sourceforge.net/

Interesting, I hadn't heard of it yet. Definitely has a steeper learning
curve for a Python developer than Cython, but it looks like C++ developers
could benefit from it.

Stefan


From philipp at achtziger.de  Wed Nov 19 18:00:11 2008
From: philipp at achtziger.de (Philipp Heuser)
Date: Wed, 19 Nov 2008 18:00:11 +0100
Subject: [capi-sig] Compiling/Linking external Functions (setup.py, distutils,
	gcc?)
Message-ID: <4924461B.4060801@achtziger.de>

Hello all,

I would like to use an existing C-Function from python. Therfore I made 
up an wrapper (wrap.c), where all the variable transformations from 
Python to C are done. That works. Now I would like to call the external 
fuction, which is placed in lets say ext_foo.a with a corresponding 
ext_foo.h  and can be used as a library from plain C.

I am assuming, that I do have to include the ext_foo.h in my wrap.c with
#include "ext_foo.h"

that I have to introduce the function in my C-Code:

extern int foo(int);

that I have to tell the setup.py using the distutils stuff where the 
library can be found...

when compiling a C-Code which is not for python usage I do type

gcc -o test.o ./test.c ./ext_foo.a -I./foo_h_file_path/

and everything is fine,
where within these setup.py files do I have to mention the ./ext_foo.a ? 
When I do place it in the sources-tag, setup procedure complains that it 
doesn't know any .a files... if I don't mention it explicitly, just 
giving the include_dirs, compilation works fine, but when importing from 
python 'import wrap' I do get the message: Symbol not found: _foo

Any help is very much appreciated!
Thanks
Philipp

From carsten.haese at gmail.com  Wed Nov 19 18:25:30 2008
From: carsten.haese at gmail.com (Carsten Haese)
Date: Wed, 19 Nov 2008 12:25:30 -0500
Subject: [capi-sig] Compiling/Linking external Functions (setup.py,
	distutils, gcc?)
In-Reply-To: <4924461B.4060801@achtziger.de>
References: <4924461B.4060801@achtziger.de>
Message-ID: <5fbcfcff0811190925h33dd1ce4p9d8ff3bffeebab8@mail.gmail.com>

On Wed, Nov 19, 2008 at 12:00 PM, Philipp Heuser <philipp at achtziger.de>wrote:

> where within these setup.py files do I have to mention the ./ext_foo.a ?
> When I do place it in the sources-tag, setup procedure complains that it
> doesn't know any .a files... if I don't mention it explicitly, just giving
> the include_dirs, compilation works fine, but when importing from python
> 'import wrap' I do get the message: Symbol not found: _foo
>

The "sources" parameter lists source files that need to be compiled. Your
ext_foo.a doesn't need to be compiled; it just needs to be linked. Try
adding a parameter link_objects=['ext_foo.a'] to the Extension(...)
definition.

HTH,

--
Carsten Haese
http://informixdb.sourceforge.net

From mal at egenix.com  Wed Nov 19 18:35:49 2008
From: mal at egenix.com (M.-A. Lemburg)
Date: Wed, 19 Nov 2008 18:35:49 +0100
Subject: [capi-sig] Compiling/Linking external Functions (setup.py,
 distutils, gcc?)
In-Reply-To: <4924461B.4060801@achtziger.de>
References: <4924461B.4060801@achtziger.de>
Message-ID: <49244E75.7020304@egenix.com>

On 2008-11-19 18:00, Philipp Heuser wrote:
> Hello all,
> 
> I would like to use an existing C-Function from python. Therfore I made
> up an wrapper (wrap.c), where all the variable transformations from
> Python to C are done. That works. Now I would like to call the external
> fuction, which is placed in lets say ext_foo.a with a corresponding
> ext_foo.h  and can be used as a library from plain C.
> 
> I am assuming, that I do have to include the ext_foo.h in my wrap.c with
> #include "ext_foo.h"
> 
> that I have to introduce the function in my C-Code:
> 
> extern int foo(int);
> 
> that I have to tell the setup.py using the distutils stuff where the
> library can be found...
> 
> when compiling a C-Code which is not for python usage I do type
> 
> gcc -o test.o ./test.c ./ext_foo.a -I./foo_h_file_path/
> 
> and everything is fine,
> where within these setup.py files do I have to mention the ./ext_foo.a ?
> When I do place it in the sources-tag, setup procedure complains that it
> doesn't know any .a files... 

The .a file is a library, so you have use the libraries parameter
to have distutils link against this library.

http://docs.python.org/extending/building.html

> if I don't mention it explicitly, just
> giving the include_dirs, compilation works fine, but when importing from
> python 'import wrap' I do get the message: Symbol not found: _foo

-- 
Marc-Andre Lemburg
eGenix.com

Professional Python Services directly from the Source  (#1, Nov 19 2008)
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>>> mxODBC.Zope.Database.Adapter ...             http://zope.egenix.com/
>>> mxODBC, mxDateTime, mxTextTools ...        http://python.egenix.com/
________________________________________________________________________
2008-11-12: Released mxODBC.Connect 0.9.3      http://python.egenix.com/

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