[PATCH] allow partial replace in string.Template

[Nick Coghlan]

Stefan Behnel wrote:
> 
> 
> Nick Coghlan wrote
> 
>> a) Patches are more likely to be looked at if placed on the SF patch 
>> tracker.
> 
> 
> see your own b), I wanted to discuss them first.

Fair enough.

> Still, when I first tried out the Template class, I immediately stumbled 
> over the fact that the substitute methods always return strings, and 
> never Template objects. While it makes sense for their primary purpose, 
> it totally restricts the usage of this module to one-show operations.

Except that it is easy to turn a string into a template using a constructor. . .

However, now that I think more about your 'partial_substitute' method it does 
make sense as an alternative constructor:

   @classmethod
   def from_template(*args, **kwds):
     cls, orig = args[:2]
     return cls(orig.safe_substitute(*args[2:], **kwds))

Usable as:
   new_templ = Template.from_template(orig_templ, *args, **kwds)

Versus:
   new_templ = Template(orig_templ.safe_substitute(*args, **kwds))

Mutating the template in place seems questionable. Rebinding the name with the 
above constructor would be more appropriate, IMO.

Hmm - I'm unconvinced, but it's probably still worth posting a patch and sending 
it in Barry Warsaw's direction.

Cheers,
Nick.

-- 
Nick Coghlan   |   ncoghlan at email.com   |   Brisbane, Australia
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