# Need clarity RASA Regex

**URL:** https://forum.rasa.com/t/need-clarity-rasa-regex/14565
**Category:** Rasa Open Source
**Created:** [August 20, 2019, 1:05pm UTC](https://forum.rasa.com/t/need-clarity-rasa-regex/14565 "2019-08-20T13:05:21Z")
**Posts on this page:** 1
**Showing post:** 3

<div class="post-metadata">

### Author: ![surya7592](https://dub1.discourse-cdn.com/flex013/user_avatar/forum.rasa.com/surya7592/32/2247_2.png) [@surya7592](https://forum.rasa.com/u/surya7592)
#### Post date: [September 2, 2019, 9:05am UTC](https://forum.rasa.com/t/need-clarity-rasa-regex/14565/3 "2019-09-02T09:05:05Z")

</div>

Hi,

This just goes against the whole idea of using regular expression.

Have included the RegexFeaturizer in the pipeline. It is capturing regex also but only capturing regex similar to the examples specified in the NLU training data. Adding more examples to training data helps but it will make the training data huge. And in our case we cannot include all possible combination of regex in the data. Because it may vary from time to time.

For example, Now it may be **ab000123** , **ac234145** , **ad3456789** but later it may change it to **zw4567257** , **zt7531598** etc.

How to take care of such cases.

---

_[View the full topic](https://forum.rasa.com/t/need-clarity-rasa-regex/14565)._