How to detect that a function argument is the default one

[Ned Batchelder]

On 12/10/14 11:10 AM, Jean-Michel Pichavant wrote:
>      self.mass = (mass is None and radius**2) or mass

When will this idiom die?  We've had actual if-expressions for a while now:

     self.mass = radius**2 if mass is None else mass

-- 
Ned Batchelder, http://nedbatchelder.com