My apologies for the confusing title.
I've run into a conceptual problem in a codebase which I'm now trying to debug from an MRE. The code to run a function defined in a Python script is
#define PY_SSIZE_T_CLEAN
#include <Python.h>
int
main(int argc, char *argv[])
{
PyObject *pName, *pModule, *pFunc;
PyObject *pArgs, *pValue;
int i;
if (argc < 3) {
fprintf(stderr,"Usage: call pythonfile funcname [args]\n");
return 1;
}
# Envvar approach to modifying the PYTHONPATH...
Py_Initialize();
# ...or using the sys library
pName = PyUnicode_DecodeFSDefault(argv[1]);
/* Error checking of pName left out */
pModule = PyImport_Import(pName);
Py_DECREF(pName);
if (pModule != NULL) {
pFunc = PyObject_GetAttrString(pModule, argv[2]);
/* pFunc is a new reference */
if (pFunc && PyCallable_Check(pFunc)) {
pArgs = PyTuple_New(argc - 3);
for (i = 0; i < argc - 3; ++i) {
pValue = PyLong_FromLong(atoi(argv[i + 3]));
if (!pValue) {
Py_DECREF(pArgs);
Py_DECREF(pModule);
fprintf(stderr, "Cannot convert argument\n");
return 1;
}
/* pValue reference stolen here: */
PyTuple_SetItem(pArgs, i, pValue);
}
pValue = PyObject_CallObject(pFunc, pArgs);
Py_DECREF(pArgs);
if (pValue != NULL) {
printf("Result of call: %ld\n", PyLong_AsLong(pValue));
Py_DECREF(pValue);
}
else {
Py_DECREF(pFunc);
Py_DECREF(pModule);
PyErr_Print();
fprintf(stderr,"Call failed\n");
return 1;
}
}
else {
if (PyErr_Occurred())
PyErr_Print();
fprintf(stderr, "Cannot find function \"%s\"\n", argv[2]);
}
Py_XDECREF(pFunc);
Py_DECREF(pModule);
}
else {
PyErr_Print();
fprintf(stderr, "Failed to load \"%s\"\n", argv[1]);
return 1;
}
if (Py_FinalizeEx() < 0) {
return 120;
}
return 0;
}
as copied almost verbatim from the Python manual.
Importing locally installed modules, however, only works sporadically—even after setting the path directly to the location of the library before calling Py_Initialize() using either from the sys standard library or setenv(3) to overwrite PYTHONPATH.
When I for example tried symlinking one of the necessary libraries, orjson, into the project directory, hereafter referred to as PROJECTDIR, I obtain an error along the lines of
File "/PROJECTDIR/orjson/__init__.py", line 1, in <module>
from .orjson import *
ModuleNotFoundError: No module named 'orjson.orjson'
numpy failed to import too, reporting
raise ImportError(msg)
ImportError:
IMPORTANT: PLEASE READ THIS FOR ADVICE ON HOW TO SOLVE THIS ISSUE!
Importing the numpy C-extensions failed. This error can happen for
many reasons, often due to issues with your setup or how NumPy was
installed.
We have compiled some common reasons and troubleshooting tips at:
https://numpy.org/devdocs/user/troubleshooting-importerror.html
Please note and check the following:
* The Python version is: Python3.11 from "/usr/bin/python3"
* The NumPy version is: "1.23.1"
and make sure that they are the versions you expect.
Please carefully study the documentation linked above for further help.
Original error was: No module named 'numpy.core._multiarray_umath'
and the troubleshooting tips don't help either. Some other libraries import flawlessly. Can anybody please explain why this happens and what I can do to fix this issue?
An edit in the spirit of giving updates: I figured it might be an environment issue, as mentioned here, but uvloop, a package mentioned in their example, does not fail to import.
