[Python-Dev] PEP 463: Exception-catching expressions

Antoine Pitrou solipsis at pitrou.net
Sat Feb 22 11:35:39 CET 2014

On sam., 2014-02-22 at 19:29 +0900, Stephen J. Turnbull wrote:
> Antoine Pitrou writes:
>  > Well, the only way to know that a key (or attribute) exists is to do
>  > the lookup. What else would you suggest?
> Do the lookup at the C level (or whatever the implementation language
> is) and generate no exception, of course.  That's what would make it
> possibly more efficient.

Let's see:
- hasattr() does the lookup at the C level, and silences the
- dict.get() does the lookup at the C level, and doesn't generate an

So apart from the minor inefficiency of generating and silencing the
AttributeError, those functions already do what you suggest.



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