Alternative to python-config callable from within Python

Question

I want to have a Python script build a Python C extension module for whichever version of the Python interpreter with which the script is being run.

To this purpose, I want to dynamically acquire the relevant C compiler flags – one way to accomplish this would be to grab the output of the python-config CLI tool, e.g. like so:

subprocess.check_output(["python-config", "--includes"])

Unfortunately, on systems on which several versions of Python are installed, this method may not find the right python-config – that is to say, the python-config associated with the currently-running version of Python. (Also, it is a bit ugly, methodologically.)

Is there some way that I can acquire this information from within Python – something perhaps like Numpy’s get_include?

Answer 1

I have the answer: it is the built-in sysconfig module.

… offering methods to access the same information python-config provides, including but not limited to:

• get_python_version() (which does what you think),
• get_paths() (yields a dict with many useful paths),
• get_config_var() and get_config_vars() (these return strings and a huge dict respectively, to sift through all of the low-level configuration options),
• get_config_h_filename() (yields the source config.h file),
• parse_config_h() (for only the most intrepid configuration plumbers)

… the first two of which will likely suffice, for anyone seeking python-config values without having to go through an embarrassing subprocess dance to get it.

• Official Python 3 sysconfig module docs
• Python 2 sysconfig PyMOTW example