LogHook for C++ Embedded Python

Redirects text send to sys.stdout/stderr from Python to a user defined C/C++ function.

When you write your own interpreter for embedded python, you are maybe interested in the output given by the Python interpreter. This header-only project provvides the functionality to pass the output to any given function.

Features

• redirect stdout/stderr to a plain function, lambda or Functor
• supports GUI programs without default console
• doesn't add any function to pythons global namespace
• doesn't add any additional python module

Requirements

• pybind11
• OR Boost.Python

If you use Boost, define TYTI_PYLOGHOOK_USE_BOOST before include PyLogHook.h.

Install

It is header only. Just add PyLogHook.h to your project which should already link against boost.python or pybind11.

How-To

Call one of the functions in namespace tyti::pylog.

// in case of using Boost.Python
#define TYTI_PYLOGHOOK_USE_BOOST 
//------------------------------

#include <PyLogHook.h>
void my_stdout(const char* w)
{
    std::cout << w;
}

void my_stderr(const char* w)
{
    std::cerr << w;
}

...

//somewhere e.g. in your main function, after Py_Initialize()
tyti::pylog::redirect_stdout(my_stdout);
tyti::pylog::redirect_stderr(my_stderr);

Preconditions

Before calling one of the functions, make sure

• python is initalized (Py_Initialize())
• you hold the GIL, if multithreading is activated

Exceptions

If anything went wrong, a Python exception was raised. You can check, if a there is a pending exception via PyErr_Occurred() (See tests).

License

MIT License © Matthias Möller. Made with ♥ in Germany.