Python C API, building a module

[P.F.C.]

I see what your saying.

Is there another way of declaring (at least) the docstring apart from the
actual array?(it would get messy otherwise)

I had also tried defining the variables as static but got the same result (I
thought static meant in code memory instead of the heap...?)

I am new to C so I may just be going about this all wrong...


-- Maranatha!
---------------------------------
PFC aka Fezzik aka GAB


On Fri, Nov 27, 2009 at 10:25 PM, MRAB <python at mrabarnett.plus.com> wrote:

> P.F.C. wrote:
>
>> Hello, I'm new to the mailing list but have been using python for a while.
>>
>> I am now attempting to embed the interpreter into a C application but am
>> having an issue when building a module exposing my application's functions
>> to python.
>> I do not know if this is the right place to ask for help with it, if it
>> isn't then please let me know where to go.
>>
>> the problem I'm having is with making a PyMethodDef array
>> When I make the array like this it works:
>>
>> static PyMethodDef ge_methods[]={
>>  {"test",ge_test,METH_NOARGS,"Test returns 123L"},
>>  {NULL,NULL}
>> };
>>
>> but as soon as I try to build the array from constant variables like this:
>>
>> const int ge_test_args = METH_NOARGS;                       //The flag for
>> this function
>> const char* ge_test_doc = "Test\nwill print \"test\"";        //The
>> docstring
>> static PyMethodDef ge_methods[]={
>>   {"test",ge_test, ge_test_args, ge_test_doc},                //simply
>> replacing the flag and the docstring with a constant variable
>>   {NULL,NULL}
>> };
>>
>> the compiler then gives the following errors:
>> ./test1.c:74: error: initializer element is not constant
>> ./test1.c:74: error: (near initialization for ‘ge_methods[0].ml_flags’)
>> ./test1.c:74: error: initializer element is not constant
>> ./test1.c:74: error: (near initialization for ‘ge_methods[0].ml_doc’)
>>
>> I'm using the gcc compiler
>>
>> This may well be because of my lack of understanding the C language but I
>> was hoping someone could help me out, or at least point me in the right
>> direction
>>
>> I also posted about this at
>> http://talk.christiandevs.com/viewtopic.php?f=13&t=2521 <
>> http://talk.christiandevs.com/viewtopic.php?f=13&t=2521>
>>
>>  I think it's because C 'const' objects aren't true constants, but are
> more like read-only variables; you can initialise them in the
> declaration but not assign to them otherwise. Thus what you're actually
> trying to do is initialise from a variable, not a constant.
> --
> http://mail.python.org/mailman/listinfo/python-list
>
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