How to specify Python 3 source in Cython's setup.py?

Question

I am trying to do a "Hello World" program in Cython, following this tutorial http://docs.cython.org/src/tutorial/cython_tutorial.html#cython-hello-world

I c

Answer 1

According to official documentation on compilation, the Python language level can be specified using a directive through a special header comment at the top of the file, like this:

#!python
#cython: language_level=3

There doesn't seem to be a way to specify this in setup.py. So if you have many Cython files, you'd have to add the compiler directive to each file. Although the only situation I've met so far that needs this directive is for print() as in your sample, and I've used Cython extensively.