I have a C++ program, I want to import a Python module and list all function names in this module. How can I do it?

I used the following code to get the dict from a module:

PyDictObject* pDict = (PyDictObject*)PyModule_GetDict(pModule);

But how to list the functions names?

Out of curiosity, I tried to puzzle this out.

First, a minimal Python module testModule.py:

def main():print("in test.main()")def funcTest():print("in test.funcTest()")

Second, a minimal C++ sample testPyModule.cc to load and evaluate the testModule:

// standard C++ header:
#include <iostream>// Python header:
#include <Python.h>int main()
{// initialize Python interpreterPy_Initialize();// run scriptconst char *const script ="# tweak sys path to make Python module of cwd locatable\n""import sys\n""sys.path.insert(0, \".\")\n";PyRun_SimpleString(script);// get module testModulePyObject *pModuleTest = PyImport_ImportModule("testModule"); // new reference// evaluate dictionary of testModulePyObject *const pDict = PyModule_GetDict(pModuleTest); // borrowed// find functionsstd::cout << "Functions of testModule:\n";PyObject *pKey = nullptr, *pValue = nullptr;for (Py_ssize_t i = 0; PyDict_Next(pDict, &i, &pKey, &pValue);) {const char *key = PyUnicode_AsUTF8(pKey);if (PyFunction_Check(pValue)) {std::cout << "function '" << key << "'\n";}}Py_DECREF(pModuleTest);// finalize Python interpreterPy_Finalize();
}

Output:

Functions of testModule:
function 'main'
function 'funcTest'

Notes:

To puzzle this out, I had to dig through the doc. pages. These are the links for the pages I used:

• Importing Modules: PyImport_ImportModule
• Module Objects: PyModule_GetDict()
• Function Objects: PyFunction_Check()
• Dictionary Objects: PyDict_Next()
• Unicode Objects and Codecs: PyUnicode_AsUTF8().

It's obvious that I didn't check any pointer for NULL (or nullptr) to keep the sample short and compact. Production code should do this, of course.