Non-python builds vs. the upcoming Python version update

Accoring to the bulletin: “On April 16th 2019, the default Python version used to run your builds will be updated from Python 2.7 to Python 3.6”

Will this update affect non language: python builds as well, e.g. language: c builds containing and testing a smallish component written in Python?

In any case, I wanted to check whether we are all good with Python 3.6, and put python: '3.6' in the .travis.yml of said language: c build, but I still got:

$ python --version
Python 2.7.6

The python key is ineffective on non-Python builds, and you are responsible for managing Python run times. I believe the run times you see on non-Python builds are the ones provided by the OS, so if you want a newer version, using a newer release (say, Xenial) or python3 (cf. https://packages.ubuntu.com/xenial/python3) might help.

Thanks.

So I take it that the default Pythong version will not change in language: c builds.
Good, because I tested with 3.5 locally, and, sadly, we are not ready yet…