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From: Joshua Landau <joshua.landau.ws@gmail.com>
Date: Thu, 4 Jul 2013 05:12:26 +0100
Subject: Re: Why this code works in python3, but not python 2:
To: Maciej Dziardziel <fiedzia@gmail.com>
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On 4 July 2013 04:52, Maciej Dziardziel <fiedzia@gmail.com> wrote:
> Out of curiosity: Does anyone know why the code below is valid in python3, but not python2:
>
> def foo(*args, bar=1, **kwargs):
>     pass

Python 3 gained syntax for keyword-only arguments.

Try "foo(1)" and it will fail -- "bar" needs to be given as a keyword.
This is because it comes after a *-expression. You can also do "def
foo(*, bar=1)" if you want bar to be keyword-only without accepting
any number of positional arguments. Python 2 does not have these, and
doesn't understand the syntax for them.