pydantic models to reference another class-CodePudding

Is it possible on a pydantic model to reference another class? For example below in the ReadRequestModel in point_type I am trying to figure out if its possible reference that only these "types of points" in a string format can be chosen:

# type-of-points
# just for reference
multiStateValue
multiStateInput
multiStateOutput
analogValue
analogInput
analogOutput
binaryValue
binaryInput
binaryOutput

And depending on what point_type is that depics what type of point_id can be chosen that I am trying to reference in the PointType class.

from typing import List, Literal, Optional
from pydantic import BaseModel


BOOLEAN_ACTION_MAPPING = Literal["active", "inactive"]


class ReadRequestModel(BaseModel):
    device_address: str
    point_type: PointType  <--- not correct
    point_id: PointType    <--- not correct


class PointType(BaseModel):
    multiStateValue: Optional[int]
    multiStateInput: Optional[int]
    multiStateOutput: Optional[int]
    analogValue: Optional[int]
    analogInput: Optional[int]
    analogOutput: Optional[int]
    binaryValue: Optional[BOOLEAN_ACTION_MAPPING]
    binaryInput: Optional[BOOLEAN_ACTION_MAPPING]
    binaryOutput: Optional[BOOLEAN_ACTION_MAPPING]


r = ReadRequestModel({'device_address': '12345:5',
                     'point_type': 'analogInput',
                      'point_id': 8})

print(r)

The idea for the request above r it should be valid because the point_type is correct (per type-of-points) and the point_id for an analogInput is an int type. Hopefully this makes sense not a lot of wisdom here but there is documentation for this on the pydantic website but I am having some difficulties trying to figure it out. Any tips appreciated.

The code above that has some major issues will just print that the point_type: PointType NameError: name 'PointType' is not defined

CodePudding user response：

Try like this:

from typing import Literal

class ReadRequestModel(BaseModel):
    device_address: str
    point_type: Literal["multiStateValue", "multiStateInput", "multiStateOutput", "analogValue", "analogInput", "analogOutput", "binaryValue", "binaryInput", "binaryOutput"]
    point_id: int

from enum import Enum

class PointTypeEnum(str, Enum):
    multiStateValue = "multiStateValue"
    multiStateInput = "multiStateInput"
    multiStateOutput = "multiStateOutput"
    analogValue = "analogValue"
    analogInput = "analogInput"
    analogOutput = "analogOutput"
    binaryValue = "binaryValue"
    binaryInput = "binaryInput"
    binaryOutput = "binaryOutput"

class ReadRequestModel(BaseModel):
    device_address: str
    point_type: PointTypeEnum
    point_id: int

This should allow you to use the PointTypeEnum class in a similar way to the Literal type, but with the added benefits of being able to iterate over the values, etc.

CodePudding user response：

Python loads module content from top to bottom. That means that you need to place your PointType definition before the ReadRequestModel and it will work