[Tutor] What is meaning of "/" in "pow(x, y, z=None, /)"?

[Steven D'Aprano]

On Tue, Aug 01, 2017 at 08:06:58PM -0500, boB Stepp wrote:

> pow(x, y, z=None, /)
>     Equivalent to x**y (with two arguments) or x**y % z (with three arguments)

It means that the arguments are positional-only, the names "x", "y" and 
"z" are for documentation purposes only. You cannot write:

pow(x=2, y=3)

but only

pow(2, 3)


> A quick scan of some of my Python books does not turn up the use of
> "/" as a function argument.

Its quite new. Up until recently, the documentation didn't distinguish 
between function parameters which can take optional keywords and those 
that can't.


-- 
Steve