Repository navigation
expose re._parse.parse_template publicly #105636
Description
Feature or enhancement
I would like to access parse_template to be able to eagerly validate that a regex replacement template is valid.
I'm using this in my python-based text editor to do find and replace. Currently I am reaching into sre_parse to get parse_template (which used to be a public-named module but was deprecated in 3.11)
I suspect this could be as simple as exposing parse_template -- my code doesn't actually care about the return value, simply whether it raises an exception or not
Activity
sobolevn commented on Jun 11, 2023
Refs #105456
AlexWaygood commented on Jun 11, 2023
Cc. @serhiy-storchaka
raghunandanbhat commented on Jun 14, 2023
I started working on this and added parse_template() in re.__init__.py
def parse_template(source, pattern): return _parse.parse_template(source, pattern)Considering the very limited amount of documentation about this function, I would appreciate some help in testing it thoroughly and writing detailed documentation.
serhiy-storchaka commented on Jun 14, 2023
Is regex replacement template validation only what you need? Or do you need more information from the result?
Over a year ago, I wrote an implementation to compile a regex replacement template. I expected that this could be used to speed up critical code, like re.compile(), but I didn't see much difference compared to implicitly caching the compiled regex replacement templates. So I excluded it from #91524.
asottile commented on Jun 14, 2023
personally I only care about validation
raghunandanbhat commented on Jul 1, 2023
Since the parse_template() raises an error when replacement template is invalid, we could just use parse_template() as it is by exposing it publicly.
I think it is redundant to implement a function just to check if a replacement template is valid, instead we could use the existing one as it is.
pythongh-105636: Add re.Pattern.compile_template()
pythongh-105636: Add re.Pattern.compile_template()
serhiy-storchaka commented on Jun 26, 2025
#135992 it is almost the same as the version written 4 years ago. It adds the compile_template() method for the pattern object which simply calls private function re._compile_template(). The type of the result is exposed as re.Template. It has minimal interface: __call__ and __class_getitem__.
asottile commented on Jun 26, 2025
ah nice! that would definitely solve my problem
asottile commented on Jun 17, 2026
unfortunate this won't make it to 3.15 (since the sre_* modules are gone gone now) -- will have to resort to some hacks until this api gets included :(