CODEWITHSUNDEEP
pythoncpython-2.7python-c-apipython-extensions
ironstein
ironstein

Reputation: 547

using a C extension in python, without installing it as a module

I am writing C extensions for python. I am just experimenting for the time being and I have written a hello world extension that looks like this : 

#include <Python2.7/Python.h>

static PyObject* helloworld(PyObject* self)
{
    return Py_BuildValue("s", "Hello, Python extensions!!");
}

static char helloworld_docs[] = "helloworld( ): Any message you want to put here!!\n";

static PyMethodDef helloworld_funcs[] = {
    {"helloworld", (PyCFunction)helloworld, METH_NOARGS, helloworld_docs},
    {NULL,NULL,0,NULL}
};

void inithelloworld(void)
{
    Py_InitModule3("helloworld", helloworld_funcs,"Extension module example!");
}

the code works perfectly fine, after installing it from a setup.py file I wrote, and installing it from command line

python setup.py install

What I want is the following :

I want to use the C file as a python extension module, without installing it, that is I want to use it as just another python file in my project, and not a file that I need to install before my python modules get to use its functionality. Is there some way of doing this ?

Upvotes: 6

Views: 2722

Answers (2)

Peter Varo
Peter Varo

Reputation: 12190

You can create your "own interpreter" by not extending python, but embedding it into your application. In that way, your objects will be always available for the users who are running your program. This is a pretty common thing to do in certain cases, for example look at the Blender project where all the bpy, bmesh and bge modules are already included.

The downside is, your users can't use the python command directly, they have to use your hello_world_python instead. (But of course you can provide your extension as a module as well.) And that also means, you have to compile and distribute your application for all platforms you want to support -- in case you want to distribute it as a binary, to make your users lives a bit easier.

For further information on embedding python into your program, read the propriate sections of the documentation:

Embedding Python in Another Application

Personal suggestion: Use Python 3.5 whenever you can, and stop supporting the old 2.x versions. For more information, read this article: Should I use Python 2 or Python 3 for my development activity?

Upvotes: 0

hmn
hmn

Reputation: 746

You can simply compile the extension without installing (usually something like python setup.py build). Then you have to make sure the interpreter can find the compiled module (for example by copying it next to a script that imports it, or setting PYTHONPATH).

Upvotes: 4

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