Pydantic ImportError

[SVyusti]

@dosu
After the following commands:
pip install langflow -U
langflow run
Got this error:
ImportError : cannot import name 'field_validator' from 'pydantic'

[dosubot[bot]]

To resolve the "ImportError: cannot import name 'field_validator' from 'pydantic'" error, you need to ensure that you are using a compatible version of Pydantic. The field_validator function is available in Pydantic v2.x, but not in earlier versions.

You can specify the version of Pydantic to install by running:

pip install pydantic==2.0.0

This should resolve the import error by ensuring that the correct version of Pydantic is installed ^[1].

To continue talking to Dosu, mention @dosu.

[SVyusti]

pydantic version being used is 2.7.3

[dosubot[bot]]

To resolve the "ImportError: cannot import name 'field_validator' from 'pydantic'" error when running langflow with Pydantic version 2.7.3, you need to update the import statements in your code. The field_validator function has been moved to a different module in Pydantic v2.

Replace:

from pydantic import field_validator

With:

from pydantic.class_validators import field_validator

Here is the updated import section of your code:

import re
import warnings
from datetime import datetime, timezone
from typing import TYPE_CHECKING, Dict, Optional
from uuid import UUID, uuid4

import emoji
from emoji import purely_emoji  # type: ignore
from fastapi import HTTPException, status
from pydantic import field_serializer
from pydantic.class_validators import field_validator
from sqlalchemy import UniqueConstraint
from sqlmodel import JSON, Column, Field, Relationship, SQLModel

from langflow.schema import Data

if TYPE_CHECKING:
    from langflow.services.database.models.folder import Folder
    from langflow.services.database.models.user import User

This change should resolve the import error ^[1][2].

To continue talking to Dosu, mention @dosu.

[Cristhianzl]

Hi! 👋

We are using other channels as our official means of communication with users. We apologize for the delayed response.
For faster assistance, please direct your questions to our Discord channel or open a GitHub issue, as we are much more active on these platforms.

Langflow Discord Server

Thank you for your understanding.

Best regards,
The Langflow Team