[Python-Dev] New syntax for 'dynamic' attribute access (original) (raw)

Collin Winter collinw at gmail.com
Tue Feb 13 22:46:41 CET 2007

On 2/13/07, Nick Coghlan <ncoghlan at gmail.com> wrote: [snip]

I've tried this out on Brett's urllib & urllib2 examples below. (calling the new builtin attrview() to emphasise the fact that it retains a reference to the original instance). I don't consider it any uglier than the proposed syntax changes, and it provides a few other benefits:

- the two-argument form is naturally available as the .get() method on the resulting dict-like object (e.g. "attrview(obj).get(someattr, None)") - hasattr() is naturally replaced by containment testing (e.g. "someattr in attrview(obj)") - keywords/builtins are easier to look up in the documentation than symbolic syntax With this approach, performance would be attained by arranging to create the view objects once, and then performing multiple dynamic attribute accesses using those view objects.

This changes my vote: +1 on including attrview(), -1 on the syntax proposal.

Collin Winter

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