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I am in Linux Mint 18 (base on Ubuntu 16.04), and I try the code in Page 27 which is

gcc $(python-config --cflags) $(python-config --ldflags) ./irrationals.c

gcc raise dozens of error like Undefined reference to ‘Py_Initialize’, when I change code to

gcc $(python-config --cflags) ./irrationals.c $(python-config --ldflags)

Everything works well. So is it a version specific bug?

Python v 2.7.12
Cython v 0.24.1
gcc v 5.4.0 (20160609)

https://www.python.org/dev/peps/pep-0632/

Where are they? I really need them.

When timing the Python/C API extension example in 01-essentials/03-timings/, I got an error like this

ImportError: dlopen( ./examples/01-essentials/03-timings/cfib.cpython-36m-darwin.so, 2): Symbol not found: _Py_InitModule
  Referenced from: ./examples/01-essentials/03-timings/cfib.cpython-36m-darwin.so
  Expected in: flat namespace
 in ./examples/01-essentials/03-timings/cfib.cpython-36m-darwin.so

The error is from line 14 in 01-essentials/03-timings/timings.py

cexttime_0 = timer(0, N, name='fib', module='cfib')

I found that Python 3.x no longer uses Py_InitModule. So this part would not work.

Here's my attempt to fix the 01-essentials/03-timings/cfib_wrap.c for Python 3.x.

The original PyMODINIT_FUNC block

PyMODINIT_FUNC
initcfib(void)
{
    (void) Py_InitModule("cfib", funcs);
}

can be replaced with

static struct PyModuleDef fib =
{
    PyModuleDef_HEAD_INIT,
    "fib",
    "",
    -1,
    funcs
};

PyMODINIT_FUNC PyInit_cfib(void) {
    return PyModule_Create(&fib);
}

This should make the example 01-essentials/03-timings to run in Python 3.x.