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Begginer in python trying to load a .dll

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  Begginer in python trying to load a .dll c1223 <camilocelyg@gmail.com> - 2014-08-12 11:36 -0700
    Re: Begginer in python trying to load a .dll Chris Angelico <rosuav@gmail.com> - 2014-08-13 04:44 +1000
    Re: Begginer in python trying to load a .dll Skip Montanaro <skip@pobox.com> - 2014-08-12 13:48 -0500
    Re: Begginer in python trying to load a .dll Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-12 19:52 +0100
    Re: Begginer in python trying to load a .dll Chris Kaynor <ckaynor@zindagigames.com> - 2014-08-12 11:55 -0700
    Re: Begginer in python trying to load a .dll c1234 py <camilocelyg@gmail.com> - 2014-08-12 11:56 -0700
      Re: Begginer in python trying to load a .dll Rob Gaddi <rgaddi@technologyhighland.invalid> - 2014-08-12 11:58 -0700
        Re: Begginer in python trying to load a .dll Chris Angelico <rosuav@gmail.com> - 2014-08-13 05:09 +1000
          Re: Begginer in python trying to load a .dll c1234 py <camilocelyg@gmail.com> - 2014-08-12 12:13 -0700
            Re: Begginer in python trying to load a .dll Laurent Pointal <laurent.pointal@laposte.net> - 2014-08-19 18:44 +0200
              Re: Begginer in python trying to load a .dll "ElChino" <elchino@cnn.cn> - 2014-08-19 19:46 +0200
    Re: Begginer in python trying to load a .dll Christian Gollwitzer <auriocus@gmx.de> - 2014-08-12 21:16 +0200
      Re: Begginer in python trying to load a .dll c1234 py <camilocelyg@gmail.com> - 2014-08-12 12:25 -0700
        Re: Begginer in python trying to load a .dll Mark Lawrence <breamoreboy@yahoo.co.uk> - 2014-08-12 21:17 +0100
          Re: Begginer in python trying to load a .dll c1234 py <camilocelyg@gmail.com> - 2014-08-13 08:25 -0700

#76130 — Begginer in python trying to load a .dll

Hi, 
Im working in the development of a program based in python that allow us to contrl a spectometer. The spectometer has an .dll file. The idea is to work through this dll and operate the spectometer. 
The name of the .dll is AS5216.dll. I've trying with ctype, but it doesn't work. 
I'm begginer in python. 
All the comments are useful to me. 

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#76132

On Wed, Aug 13, 2014 at 4:36 AM, c1223 <camilocelyg@gmail.com> wrote:
> Im working in the development of a program based in python that allow us to contrl a spectometer. The spectometer has an .dll file. The idea is to work through this dll and operate the spectometer.
> The name of the .dll is AS5216.dll. I've trying with ctype, but it doesn't work.
> I'm begginer in python.
> All the comments are useful to me.

What have you tried, exactly? What does "it doesn't work" mean?

Interfacing with a DLL is a potentially very hard and complex job
(although it might turn out to be really easy - depends what the DLL's
doing). We can't simply give you an answer right here, without knowing
heaps about the DLL you're working with - where it came from, whether
this is homework or a real-world problem, etc, etc, etc.

ChrisA

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#76134

On Tue, Aug 12, 2014 at 1:36 PM, c1223 <camilocelyg@gmail.com> wrote:
> I've trying with ctype, but it doesn't work.

Can you post a small example of how you're trying to use cypes? I
don't think a full example would be necessary, but knowing the API of
one or two functions and how you're trying to call them from Python
would be useful.

Just as the off-chance your DLL was written in C++... I don't think
you can interface with ctypes directly. I think you would have to
write a little shim DLL which exposes a C-compatible API.

Skip

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#76135

On 12/08/2014 19:36, c1223 wrote:
> Hi,
> Im working in the development of a program based in python that allow us to contrl a spectometer. The spectometer has an .dll file. The idea is to work through this dll and operate the spectometer.
> The name of the .dll is AS5216.dll. I've trying with ctype, but it doesn't work.
> I'm begginer in python.
> All the comments are useful to me.
>

Please help us to help you.  Stating "it doesn't work" is of no use. 
Show us your code, what you expected to happen and what actually 
happened.  If you get a traceback cut and paste all of it into your 
message.  State what version of Python you have and your OS.  Sure 
seeing dll we can surmise Windows but which one?

For further advice on how to put your question(s) together see "The 
SSCCE - Short, Self Contained, Correct (Compilable), Example" at 
http://sscce.org/

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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#76137

[Multipart message — attachments visible in raw view] — view raw

On Tue, Aug 12, 2014 at 11:48 AM, Skip Montanaro <skip@pobox.com> wrote:

> Just as the off-chance your DLL was written in C++... I don't think
> you can interface with ctypes directly. I think you would have to
> write a little shim DLL which exposes a C-compatible API.
>

You should be able to use ctypes with a C++ library, you'd just need to
know how your C++ compiler handles name mangling. Typically, changes are
made to accommodate classes, namespaces, and function overloads. Of course,
if you were to change to a different compiler (possibly including a
different version) or made minor tweaks to the functions, you'd have to
update all the Python code to use the new name mangling scheme.

Hmm...On second thought, maybe just only using functions exports with
"extern C" would be easier - or just using a C compiler.

Chris

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#76138

On Tuesday, August 12, 2014 3:36:17 PM UTC-3, c1234 py wrote:
> Hi, 
> 
> Im working in the development of a program based in python that allow us to contrl a spectometer. The spectometer has an .dll file. The idea is to work through this dll and operate the spectometer. 
> 
> The name of the .dll is AS5216.dll. I've trying with ctype, but it doesn't work. 
> 
> I'm begginer in python. 
> 
> All the comments are useful to me.


I'm using this


>>import ctypes
hllDll=ctypes.WinDLL("C:\\AS5216.dll")


hllApiProto = ctypes.WINFUNCTYPE (ctypes.c_int,ctypes.c_void_p,
    ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p)
hllApiParams = (1, "p1", 0), (1, "p2", 0), (1, "p3",0), (1, "p4",0),


hllApi = hllApiProto (("HLLAPI", hllDll), hllApiParams)

p1 = ctypes.c_int (1)
p2 = ctypes.c_char_p (sessionVar)
p3 = ctypes.c_int (1)
p4 = ctypes.c_int (0)
hllApi (ctypes.byref (p1), p2, ctypes.byref (p3), ctypes.byref (p4))



Thanks

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#76139

On Tue, 12 Aug 2014 11:56:37 -0700 (PDT)
c1234 py <camilocelyg@gmail.com> wrote:

> On Tuesday, August 12, 2014 3:36:17 PM UTC-3, c1234 py wrote:
> > Hi, 
> > 
> > Im working in the development of a program based in python that allow us to contrl a spectometer. The spectometer has an .dll file. The idea is to work through this dll and operate the spectometer. 
> > 
> > The name of the .dll is AS5216.dll. I've trying with ctype, but it doesn't work. 
> > 
> > I'm begginer in python. 
> > 
> > All the comments are useful to me.
> 
> 
> I'm using this
> 
> 
> >>import ctypes
> hllDll=ctypes.WinDLL("C:\\AS5216.dll")
> 
> 
> hllApiProto = ctypes.WINFUNCTYPE (ctypes.c_int,ctypes.c_void_p,
>     ctypes.c_void_p, ctypes.c_void_p, ctypes.c_void_p)
> hllApiParams = (1, "p1", 0), (1, "p2", 0), (1, "p3",0), (1, "p4",0),
> 
> 
> hllApi = hllApiProto (("HLLAPI", hllDll), hllApiParams)
> 
> p1 = ctypes.c_int (1)
> p2 = ctypes.c_char_p (sessionVar)
> p3 = ctypes.c_int (1)
> p4 = ctypes.c_int (0)
> hllApi (ctypes.byref (p1), p2, ctypes.byref (p3), ctypes.byref (p4))
> 
> 

Great.  And that fails in what way, on which line, with what error message?


-- 
Rob Gaddi, Highland Technology -- www.highlandtechnology.com
Email address domain is currently out of order.  See above to fix.

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#76141

On Wed, Aug 13, 2014 at 4:58 AM, Rob Gaddi
<rgaddi@technologyhighland.invalid> wrote:
> Great.  And that fails in what way, on which line, with what error message?

And, is that the entire program? Because if it is, then I can see at
least one problem, a NameError.

ChrisA

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#76142

On Tuesday, August 12, 2014 4:09:13 PM UTC-3, Chris Angelico wrote:
> On Wed, Aug 13, 2014 at 4:58 AM, Rob Gaddi
> 
> <rgaddi@technologyhighland.invalid> wrote:
> 
> > Great.  And that fails in what way, on which line, with what error message?
> 
> 
> 
> And, is that the entire program? Because if it is, then I can see at
> 
> least one problem, a NameError.
> 
> 
> 
> ChrisA

This appear in the terminal:


>>> runfile('C://Python Scripts')
  File "C:\\sitecustomize.py", line 585, in runfile
    execfile(filename, namespace)
  File "C://Sin título 38.py", line 19, in <module>
    hllApi = hllApiProto (("HLLAPI", hllDll), hllApiParams)
AttributeError: function 'HLLAPI' not found
>>> Traceback (most recent call last):
  File "<stdin>", line 1, in <module>

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#76577

c1234 py wrote:

> This appear in the terminal:
> 
> 
>>>> runfile('C://Python Scripts')
>   File "C:\\sitecustomize.py", line 585, in runfile
>     execfile(filename, namespace)
>   File "C://Sin título 38.py", line 19, in <module>
>     hllApi = hllApiProto (("HLLAPI", hllDll), hllApiParams)
> AttributeError: function 'HLLAPI' not found
>>>> Traceback (most recent call last):
>   File "<stdin>", line 1, in <module>

So you must find the (exact) name(s) exported by the DLL.

On Linux ther is objdump.

On Windows there is dumpbin
http://msdn.microsoft.com/en-us/library/c1h23y6c%28v=vs.100%29.aspx

On Windows, google also found this graphical tool:
http://www.dependencywalker.com/

A+

PS. If you have a C header file, it may be more easy to correctly build 
the ctype mapping (and if its not too big and filled of private 
property code, show it).

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#76587

"Laurent Pointal" <laurent.pointal@laposte.net> wrote:

> On Windows there is dumpbin
> http://msdn.microsoft.com/en-us/library/c1h23y6c%28v=vs.100%29.aspx
> 
> On Windows, google also found this graphical tool:
> http://www.dependencywalker.com/

PEdump is also a great tool:
  http://www.wheaty.net/pedump.zip

Includes source too.

--gv

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#76143

Am 12.08.14 20:36, schrieb c1223:
> Hi, Im working in the development of a program based in python that
> allow us to contrl a spectometer. The spectometer has an .dll file.
> The idea is to work through this dll and operate the spectometer. The
> name of the .dll is AS5216.dll. I've trying with ctype, but it
> doesn't work. I'm begginer in python. All the comments are useful to
> me.

For sure this DLL will come with a header file for C. You could pass it 
through SWIG and see if it generates a useful Python module. You need a 
C compiler for that route, though.

	Christian

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#76145

El martes, 12 de agosto de 2014 16:16:21 UTC-3, Christian Gollwitzer  escribió:
> Am 12.08.14 20:36, schrieb c1223:
> 
> > Hi, Im working in the development of a program based in python that
> 
> > allow us to contrl a spectometer. The spectometer has an .dll file.
> 
> > The idea is to work through this dll and operate the spectometer. The
> 
> > name of the .dll is AS5216.dll. I've trying with ctype, but it
> 
> > doesn't work. I'm begginer in python. All the comments are useful to
> 
> > me.
> 
> 
> 
> For sure this DLL will come with a header file for C. You could pass it 
> 
> through SWIG and see if it generates a useful Python module. You need a 
> 
> C compiler for that route, though.
> 
> 
> 
> 	Christian


How can i pass it through a SWIG?, i don't know that and what it mean?

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#76149

On 12/08/2014 20:25, c1234 py wrote:
> El martes, 12 de agosto de 2014 16:16:21 UTC-3, Christian Gollwitzer  escribió:
>> Am 12.08.14 20:36, schrieb c1223:
>>
>>> Hi, Im working in the development of a program based in python that
>>
>>> allow us to contrl a spectometer. The spectometer has an .dll file.
>>
>>> The idea is to work through this dll and operate the spectometer. The
>>
>>> name of the .dll is AS5216.dll. I've trying with ctype, but it
>>
>>> doesn't work. I'm begginer in python. All the comments are useful to
>>
>>> me.
>>
>>
>>
>> For sure this DLL will come with a header file for C. You could pass it
>>
>> through SWIG and see if it generates a useful Python module. You need a
>>
>> C compiler for that route, though.
>>
>>
>>
>> 	Christian
>
>
> How can i pass it through a SWIG?, i don't know that and what it mean?
>

Start here http://www.swig.org/ which you could easily have found for 
yourself, as I did by using a search engine.

Also would you please access this list via 
https://mail.python.org/mailman/listinfo/python-list or read and action 
this https://wiki.python.org/moin/GoogleGroupsPython to prevent us
seeing double line spacing and single line paragraphs, thanks.

-- 
My fellow Pythonistas, ask not what our language can do for you, ask
what you can do for our language.

Mark Lawrence

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#76207

Thanks a lot. 



El martes, 12 de agosto de 2014 17:17:26 UTC-3, Mark Lawrence  escribió:
> On 12/08/2014 20:25, c1234 py wrote:
> 
> > El martes, 12 de agosto de 2014 16:16:21 UTC-3, Christian Gollwitzer  escribi�:
> 
> >> Am 12.08.14 20:36, schrieb c1223:
> 
> >>
> 
> >>> Hi, Im working in the development of a program based in python that
> 
> >>
> 
> >>> allow us to contrl a spectometer. The spectometer has an .dll file.
> 
> >>
> 
> >>> The idea is to work through this dll and operate the spectometer. The
> 
> >>
> 
> >>> name of the .dll is AS5216.dll. I've trying with ctype, but it
> 
> >>
> 
> >>> doesn't work. I'm begginer in python. All the comments are useful to
> 
> >>
> 
> >>> me.
> 
> >>
> 
> >>
> 
> >>
> 
> >> For sure this DLL will come with a header file for C. You could pass it
> 
> >>
> 
> >> through SWIG and see if it generates a useful Python module. You need a
> 
> >>
> 
> >> C compiler for that route, though.
> 
> >>
> 
> >>
> 
> >>
> 
> >> 	Christian
> 
> >
> 
> >
> 
> > How can i pass it through a SWIG?, i don't know that and what it mean?
> 
> >
> 
> 
> 
> Start here http://www.swig.org/ which you could easily have found for 
> 
> yourself, as I did by using a search engine.
> 
> 
> 
> Also would you please access this list via 
> 
> https://mail.python.org/mailman/listinfo/python-list or read and action 
> 
> this https://wiki.python.org/moin/GoogleGroupsPython to prevent us
> 
> seeing double line spacing and single line paragraphs, thanks.
> 
> 
> 
> -- 
> 
> My fellow Pythonistas, ask not what our language can do for you, ask
> 
> what you can do for our language.
> 
> 
> 
> Mark Lawrence

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