Fastapi: Validate List[str] using regex

[marius-benthin]

Hello :)

How do I validate a list of strings that are sent via POST parameters?

I have this example ...

@app.post("/entity/list")
def query_entity_list(entities: List[str] = Query(None, regex="^[a-z]{5}$")):
   return entities

... and the API function is called by ...

curl -X POST "http://localhost/entity/list/?entities=valid&entities=inv4lid

Is it possible to apply the regex on each item in the entities list?
Currently, the string validation does not working for me.

Thanks in advance!

[sm-Fifteen]

You would want to have a specific string type with that contraint. Pydantic has a ConstrainedStr/constr type spcifically for that purpose:

from pydantic import constr

EntryCode = constr(regex="^[a-z]{5}$")

@app.post("/entity/list")
def query_entity_list(entities: List[EntryCode] = Query(None)):
   return entities

[marius-benthin]

Thank you very much @sm-Fifteen! It works now :)

[tiangolo]

Thanks for the help here @sm-Fifteen ! :cake:

Thanks @marius-benthin for reporting back and closing the issue :+1: