I think having math.pi is just for backward compatibility. We all use tau now, I assume. That's why the true definition is:

  pi = math.tau/2


... and yes, as someone else comments, adding tau was a bit whimsical in the spirit of 'import antigravity' and the line.

On Jun 1, 2017 12:48 AM, "Serhiy Storchaka" <storchaka@gmail.com> wrote:
01.06.17 10:03, David Mertz пише:

It's awfully easy to add in your own code. Since they are simply aliases, I don't see why bother put the duplication in the standard library. You can even monkey patch if you want it in the 'math' namespace. I'd prefer a bare 'π' in my own code though.

As well as adding tau = 2*math.pi in your own code. But this deserved the whole PEP and was added as a feature in 3.6.

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