Pydantic: How to throw an error for an empty input value?

[rappongy]

Question

Hello! Does any common way to throw an error for an empty input value?

Example:

class Foo(pydantic.BaseModel):
    bar: str

# Wanna throw an error in this case
Foo(bar="")

Thank you for your work.

[koxudaxi]

You can use constr as a type.

from pydantic import constr, BaseModel


class Model(BaseModel):
    bar: constr(min_length=1)


Model(bar="")

https://pydantic-docs.helpmanual.io/usage/types/#constrained-types

[samuelcolvin]

or you can use validators