How to determine lowest version of Python 3 to run?

[Ben Finney]

Christopher Reimer <christopher_reimer at icloud.com> writes:

> How do I determine the lowest version of Python to [declare that my
> code supports]?

You can determine that by installing all the Python versions you want to
try, and running your code's unit test suite on each of them.

Those versions where the unit test suite fails, you can know that your
code does not run on that version of Python.

do this each time you make a significant change to the code; certainly
before you release any changes to the world.

Automate this procedure with an automated testing tool such as Tox
<URL:https://tox.readthedocs.org/>.

> I'm leaning towards installing the latest minor version of each
> available major version, running tox to run the unit tests against
> each one, and seeing what blows up.

That sounds to me like a good approach.

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Ben Finney