[New-bugs-announce] [issue5383] Allow intermixing of keyword arguments and vargarg arguments

[David Kerkeslager]

New submission from David Kerkeslager <david.kerkeslager at gmail.com>:

This problem arose in this thread:
http://www.python-forum.org/pythonforum/viewtopic.php?f=2&t=11606

Basically, we have the following function which will generate an XHTML 
node:

def xhtmlNode(tag, *content, **attr):...

If we call:

xhtmlNode('div',id='sidebar','Hello, world')

... it should generate the xhtml:

<div id='sidebar'>Hello, world</div>

However, this isn't possible because the keyword argument isn't allowed 
to come before the 'vararg' argument.  We could do this:

xhtmlNode('div','Hello, world',id='sidebar')

... but this would not have symmetry with the generated xhtml and 
therefore complicates the code.  The solution, in my opinion, is to 
allow varargs to be intermixed with keyword args.  The above real-world 
example shows a use-case for this more flexible functionality.

If the following rules apply, there shouldn't be any issues:
1. Positional arguments must be in their position (positional arguments 
must come before all 'vararg' arguments and keyword arguments).
2. Varargs come in the order in which they are received, ignoring any 
keyword arguments that are intermixed.
3. Keyword arguments order doesn't matter (a dictionary isn't ordered).  
They can be intermixed with varargs.

Thus the following call:

xhtmlNode('div',id='sidebar',style='width:100px;float:left;','Hello,worl
d',xhtmlNode('p','Hello, world'))

... would result in the following html:

<div id='sidebar' style='width:100px;float:left;'> Hello, world 
<p>Hello, world</p></div>

----------
messages: 82839
nosy: Imagist
severity: normal
status: open
title: Allow intermixing of keyword arguments and vargarg arguments

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Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue5383>
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