<div class="gmail_quote">On Thu, Mar 24, 2011 at 10:51, Jameson Quinn <span dir="ltr"><<a href="mailto:jameson.quinn@gmail.com">jameson.quinn@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Consider:<div><br></div><div>def fun1(argument):</div><div> print argument1</div><div><br></div><div>fun1(argument="spam")</div><div><br></div><div>def fun2(**kw):</div><div> print kw["argument"]</div>
<div><br></div><div>Why should I need quotes around "argument" in just one of those places? What if I left them off, and there happened to be a global variable named "argument"? Why shouldn't I be able to say:</div>
<div><br></div><div>def fun2(**kw):</div><div> print kw..argument</div><div><br></div><div>(in real life, there would be a try... except block in case there was no argument, I'm just showing the simplest case here.)</div>
</blockquote><div><br></div><div>I can certainly see use cases for this, but none generic enough for the standard library.</div><div><br></div><div>Let's take the configparser module for example: in 3.2 ConfigParser objects can now be accessed like dictionaries. Looking at the examples in the documentation [0], an immediate problem comes to mind:</div>
<div><br></div><div> print(config..bitbucket.org..user)</div><div> *boom*</div><div><br></div><div>If you're going to be doing attribute access, it's likely that you know the name of the attribute -- you wrote the code knowing what to expect in the first place. If you know the names of the attributes you're going to be dealing with, why not just store them in a class, or even a class with __slots__ defined for each attribute?</div>
<div><br></div><div>The double-dot notation will only work when you already know the key. When iterating over keys, you're going to resort back to dict[key] or getattr(dict, key) to get the value.</div><div><br></div>
<div>In the end, it's syntactic sugar for a limited set of applicable cases.</div><div><br></div><div><br></div><div><br></div><div>[0] <a href="http://docs.python.org/release/3.2/library/configparser">http://docs.python.org/release/3.2/library/configparser</a></div>
</div>