math.nroot [was Re: A brief question.]

[Tim Peters]

[Steven D'Aprano]
...
> But this works:
> 
> py> inf = float("inf")
> py> inf
> inf

Another platform-dependent accident.  That does not work, for example,
on Windows.  In fact, the Microsoft C float<->string routines don't
support any way "to spell infinity" that works in the string->float
direction.