Import C++ files directly from Python!
Project description
Import C or C++ files directly from Python!
Let’s try it out. First, if you’re on Linux or OS X, install with the terminal command pip install cppimport.
Here’s a simple C++ extension using pybind11:
<%
setup_pybind11(cfg)
%>
#include <pybind11/pybind11.h>
namespace py = pybind11;
int square(int x) {
return x * x;
}
PYBIND11_PLUGIN(somecode) {
pybind11::module m("somecode", "auto-compiled c++ extension");
m.def("square", &square);
return m.ptr();
}Save this code as somecode.cpp.
Open a python interpreter and run these lines [1]:
>>> import cppimport
>>> somecode = cppimport.imp("somecode") #This will pause for a moment to compile the module
>>> somecode.square(9)
81I’m a big fan of the workflow that this enables, where you can edit both C++ files and Python and recompilation happens transparently.
What’s actually going on?
The technical description: cppimport looks for a C or C++ source file that matches the requested module. If such a file exists, the file is compiled as a Python extension using the options in a Mako header. The extension (shared library) that is produced is placed in the same folder as the C++ source file. Then, the extension is loaded.
Simpler language please: Sometimes Python just isn’t fast enough. Or you have existing code in a C++ library. So, you write a Python extension module, a library of compiled code. I recommend pybind11 for C++ to Python bindings or cffi for C to Python bindings. I’ve done this a lot over the years. But, I discovered that my productivity goes through the floor when my development process goes from Edit -> Test in just Python to Edit -> Compile -> Test in Python plus C++. So, cppimport combines the process of compiling and importing an extension in Python so that you can type modulename = cppimport.imp("modulename") and not have to worry about multiple steps. Internally, when no matching Python module is found, cppimport looks for a file modulename.cpp. If one is found, it’s compiled and loaded as an extension module.
Notes
cppimport uses the MIT License
Release history Release notifications | RSS feed
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
