Rasa forms slot - restrict to single value

In rasa form for a entity, it is assigning list to a slot. How to restrict slot to take only one value not a list ?

Ex : the flow is as below while using form

    * user_bank_name{"bankname":"adib"}
     - slot{"bankname":"adib"}
     - form_personal_loan
     - slot{"bankname":["adib","adib"]}

Not sure how you ended up there. Is that a training story?

However, you end up with a list in a slot when you get multiple entities that are mapped to this slot in a single message.

Example: User: I want to go to Dubai and Ulan Bartor

Now the bot recoginizes ‘Dubai’ and ‘Ulan Bartor’ as city entity and got a slot with the same name, you’ll get a list ([‘Dubai’, ‘Ulan Bartor’]) as the slot value. Your chance to control this, is the {slotname}_validate method, where you can write your own logic to handle this.

Thank you for your reply. Coming to story part, I am using rasa x to test forms and create story, i have bank names in nlu as below

- [Dubai Islamic Bank](bankname) bank
- [National Bank of Fujairah](bankname) bank
- [national bank of fujairah](bankname) bank
- [adib](bankname)

When i enter ‘adib’, nlu is getting changed to (adib is added to nlu)

- [Dubai Islamic Bank](bankname) bank
- [National Bank of Fujairah](bankname) bank
- [national bank of fujairah](bankname) bank
- [adib](bankname)[adib](bankname)