What method can I use instead of __file__ in python?

Question

I convert my python code to c by cython and after that compile .c file and use .so in my project. My problem: I use __file__ in my python code and in while compile by gcc, it doesn't get error. but when I run program and import .so in other python files, appear an error from __file__ line.

How can solve this problem? Is there any method to replace with __file__?

Jed

What do you use it for? – Radtke

__file__ does now work on recent versions of Cython (>0.27) when run on Python 3.5+. – Gauvin

__file__ gives me "built-in" instead of the filename in Cython >0.29 on Python 3.7.0 – Demob

Answer 1

Try to add this at the beginning of your file:

import inspect
import sys
if not hasattr(sys.modules[__name__], '__file__'):
    __file__ = inspect.getfile(inspect.currentframe())

Drain

That only works for Python code stack frames, not for C extensions. – Crissum

If you only need to get a package root path in Cython module, but __file__ is not defined due to the Python bug bugs.python.org/issue13429, then you can use a simple trick by referencing __init__.py: def get_package_root(): from . import __file__ as initpy_file_path; return os.path.dirname(initpy_file_path) – Aerothermodynamics

@MartijnPieters what is your suggestion for C extensions? – Sensationalism

This answer didn't work correctly for me, it was returning cwd, while Vlad Frolov answer did the job! – Klystron

Answer 2

Not too sure how you will make it python compatible but gcc #defines __FILE__ for the name of the file that the code is in.

Ulla

Answer 3

why not use sys.argv[0] ?

This works even when it's compiled into a cython executable.

Hysteresis

But doesn't work in any other case. You're often using __file__ to work out where a module is installed – Gauvin