# Template key regex filter with | or? **URL:** \ **Category:** Pipeline Integrations\ **Created:** [July 7, 2020, 10:11am UTC](https://community.shotgridsoftware.com/t/template-key-regex-filter-with-or/9276 "2020-07-07T10:11:31Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![rthompson](https://sea1.discourse-cdn.com/shotgunsoftware/user_avatar/community.shotgridsoftware.com/rthompson/32/1728_2.png) [@rthompson](https://community.shotgridsoftware.com/u/rthompson)\ **Post date:** [July 7, 2020, 10:11am UTC](https://community.shotgridsoftware.com/t/template-key-regex-filter-with-or/9276/1 "2020-07-07T10:11:31Z")
I am trying to apply a filter\_by: regex to one of our keys in our templates to accommodate the following: 1. VDC3310 2. 167\_VAL\_1560 I’ve tried many different systems involving a|b switches and (a)? optional blocks, but the filter system seems to reject both of those. I have figured out a regex that does work without those optional blocks, but I’d really like to know if and how I can include those OR switches and optional groups for future reference in case we have more non-conforming shot names to deal with. Thanks. Edit: I’ve already read both these articles, which imply that any valid regex should work, but that simply does not seem to be the case for filter\_by in the templates. > **[Integrations File System Reference](https://support.shotgunsoftware.com/hc/en-us/articles/219039868-Integrations-File-System-Reference)** > > File System Configuration Reference > > > > This document is a complete reference of the file system centric configurations in the Shotgun Pipeline Toolki... [https://developer.shotgunsoftware.com/tk-core/core.html](https://developer.shotgunsoftware.com/tk-core/core.html) ---
**Author:** ![DavidMason](https://sea1.discourse-cdn.com/shotgunsoftware/user_avatar/community.shotgridsoftware.com/davidmason/32/193_2.png) [@DavidMason](https://community.shotgridsoftware.com/u/DavidMason)\ **Post date:** [July 7, 2020, 10:17am UTC](https://community.shotgridsoftware.com/t/template-key-regex-filter-with-or/9276/2 "2020-07-07T10:17:02Z")
Hi @rthompson, I’ll check with our Reg-Expert 😉 to see if they can help with this. Are you able to share with us the filter/s you believe should work that are not? -David ---
**Author:** ![rthompson](https://sea1.discourse-cdn.com/shotgunsoftware/user_avatar/community.shotgridsoftware.com/rthompson/32/1728_2.png) [@rthompson](https://community.shotgridsoftware.com/u/rthompson)\ **Post date:** [July 7, 2020, 10:22am UTC](https://community.shotgridsoftware.com/t/template-key-regex-filter-with-or/9276/3 "2020-07-07T10:22:08Z")
Gladly. I tested all of these (and some others I can’t recall) using the website [https://www.regextester.com/](https://www.regextester.com/) As well as a Python test script, just to be sure they were valid. They all should have worked according to those tests, but none of them did… ```auto filter_by: '\b([0-9a-zA-Z]+(_\w{1,3}_\d{1,4})?)' filter_by: '(^[0-9a-zA-Z]+(_\w{1,3}_\d{1,4})?)' filter_by: '\b([0-9a-zA-Z]+)(_\w{1,3}_\d{1,4})?' filter_by: '(^[0-9a-zA-Z]+)(_\w{1,3}_\d{1,4})?' filter_by: '^[0-9a-zA-Z]+(_\w{1,3}_\d{1,4})*' filter_by: '(^\d+_\w+_\d+)|(^[0-9a-zA-Z-]+)' filter_by: '^\d+_\w+_\d+|^[0-9a-zA-Z-]+' filter_by: '^(^\d{1,3}_\w{1,3}_\d{1,4}|[0-9a-zA-Z-]+)' ``` ---
**Author:** ![tannaz](https://sea1.discourse-cdn.com/shotgunsoftware/user_avatar/community.shotgridsoftware.com/tannaz/32/32_2.png) [@tannaz](https://community.shotgridsoftware.com/u/tannaz)\ **Post date:** [July 10, 2020, 12:37am UTC](https://community.shotgridsoftware.com/t/template-key-regex-filter-with-or/9276/4 "2020-07-10T00:37:08Z")
Hi @rthompson, I’m not sure what the problem was with the regexes that you tried, but I can show you one that worked for me: `'[0-9]{0,3}_?[A-Z]{3}_?[0-9]{4}'` ### First, to talk through the regex: - `[0-9]{0,3}` : 0-3 digit characters. (I’m sure you could replace the `[0-9]` with `\d`.) Allowing `0` of these makes it optional by nature. - `_?`: optional underscore - `[A-Z]{3}`: exactly 3 uppercase letters - `_?`: second optional underscore - `[0-9]{4}`: exactly 4 digit characters ### How I tested it: - I created the following template key in `templates.yml`, using the above regex: ```auto Shot: type: str filter_by: '[0-9]{0,3}_?[A-Z]{3}_?[0-9]{4}' ``` - I created Shots called `VDC331` and `167_VAL_1560` on my test project. - I used `tank shell` to get an interactive Python session with an existing Toolkit API handle called `tk`. ```auto >>> template_obj = tk.templates['maya_shot_work'] # test 1: 167_VAL_1560 >>> fields = {'Shot': '167_VAL_1560', 'Step': 'comp', 'name': 'test', 'version': 3, 'Sequence': 'sq200'} >>> template_obj.apply_fields(fields) '/sgtk/projects/goats/sequences/sq200/167_VAL_1560/comp/work/maya/test.v003.ma' # test 2: VDC3310 >>> fields = {'Shot': 'VDC3310', 'Step': 'comp', 'name': 'test', 'version': 3, 'Sequence': 'sq200'} >>> template_obj.apply_fields(fields) '/sgtk/projects/goats/sequences/sq200/VDC3310/comp/work/maya/test.v003.ma' # test 3: s009, which should *not* match the filter regex: >>> fields = {'Shot': 's009', 'Step': 'comp', 'name': 'test', 'version': 3, 'Sequence': 'sq200'} >>> template_obj.apply_fields(fields) Traceback (most recent call last): File "", line 1, in File "/sgtk/software/shotgun/goats/install/core/python/tank/template.py", line 260, in apply_fields return self._apply_fields(fields, platform=platform) File "/sgtk/software/shotgun/goats/install/core/python/tank/template.py", line 604, in _apply_fields fields, ignore_types, platform, skip_defaults=skip_defaults File "/sgtk/software/shotgun/goats/install/core/python/tank/template.py", line 317, in _apply_fields value, ignore_type=ignore_type File "/sgtk/software/shotgun/goats/install/core/python/tank/templatekey.py", line 229, in str_from_value raise TankError(self._last_error) TankError: Illegal value 's009' does not fit filter_by '[0-9]{0,3}_?[A-Z]{3}_?[0-9]{4}' ``` So, using the `?` operator for optional characters does indeed work – it correctly matched the two Shots we expected it to match, and errored on the one that didn’t. I’m not sure what the specific issue was with the regexes that you tested, but maybe start with mine and then make modifications to make it match your exact use case? Let me know if you’re still stuck, and we can keep digging.