[Python-Dev] Re: Update PEP 292

[Raymond Hettinger]

> [Raymond Hettinger]
> > However, I think we should follow Cheetah's example.
> 
> Sorry, I never heard of Cheetah before you mentioned it (& still don't
> know what it is), so feel no pressure to ape it.

I'm surprised that we're introducing a new API into the standard library
and no one is showing the slightest interest in prior art.  Cheetah is
well thought out, fast, and mature (it's been through several evolutions
in the wild).  Also, the Cheetah designers started out by studying the
existing art from ASP, JSP, PHP, PSP, and such.  Templating and string
substituion is not a new, yet the discussion here has the flavor of
being thought up from scratch.



> > That's makes it less of a pita when the template naturally contains
> > dollar signs with numbers:
> 
> I don't care.  The minority of Americans who want to use $ in a
> minority of templated strings in a minority of apps can learn to type
> $$, or use the ironically named SafeTemplate instead (as suggested
> earlier).
> 
> > Template("Dear ${donor}, send $100.00 to the PSF template fund.")
> 
> Which would trigger an exception, after which they type one character
> to repair it:
> 
> Template("Dear ${donor}, send $$100.00 to the PSF template fund.")


FWIW, I'm fine with that.  It was a minor suggestion.  Either way works.

My thought was that simpler string substitutions were going to be
exposed to the end-user (non-programmers) and that they should not be
harassed unnecessarily.  However, these are easy errors to trap and
report back to the user -- the only question being how to assign a line
number to the exception (if I have a ten page user supplied template
with an error, it would be great to tell them where it is).



Raymond









> 
> They'll live, but not at everyone else's expense.  They're already
> confused, or they wouldn't have bothered with the unnecessary braces
> around "donor" <wink>.