pydantic : duplicate validator function

Question

I used the code below: It shows duplicated validator. Why cannot use both? How do I create an alias in the @validator if I cannot use Field?

from pydantic import BaseModel, validator, Field
import datetime

class MultiSourceInput(BaseModel):
    abc :   str = Field(..., alias= 'abc_1',description= "xxxxxxxxxxxx.")
    xyz :   int= Field(..., description= "xxxxxxxx ",ge=0, le=150)

    @validator("abc")
    def abc(value): 
        values = float(value) 
        if value <=141 and value>=0: 
            return value
        else:
            0

Here's the traceback:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "<stdin>", line 37, in MultiSourceInput
  File "pydantic/class_validators.py", line 85, in pydantic.class_validators.validator.dec
  File "pydantic/class_validators.py", line 144, in pydantic.class_validators._prepare_validator
pydantic.errors.ConfigError: duplicate validator function "__main__.MultiSourceInput.abc"; if this is intended, set `allow_reuse=True`

Answer 1

In my case, this occurred because the validation method was receiving self instead of cls, meaning:

    @validator("my_field")
    def parse_my_field(self, v):
        ...

Instead of:

    @validator("my_field")
    def parse_my_field(cls, v):
        ...

Answer 2

My issue was caused by errors (seemingly unrelated) earlier in the code. Some knock-on effects caused the duplicate validator function error. When I fixed the preceding errors this went away

Answer 3

Check if there is a validator created with abc method name. You might need to rename the method