Two questions about efficiency

[Steve M]

Peter Otten <__peter__ at web.de> wrote
<snip>
> Two results stand out: misses are cheap for DictIn and expensive for
> DictTry.

That's very interesting, thanks so much Peter and the others. 

So, contrary to your (and, incidentally, Wittgenstein's) admonition to
look not think, why, would you speculate, is this the case? The
overhead from creating an exception object?