Short way to get all field names of a pydantic class

Question

Minimal example of the class:

from pydantic import BaseModel

class AdaptedModel(BaseModel):
    def get_all_fields(self, alias=False):
        return list(self.schema(by_alias=alias).get("properties").keys())

class TestClass(AdaptedModel):
    test: str

The way it works:

dm.TestClass.get_all_fields(dm.TestClass)

Is there a way to make it work without giving the class again?

Desired way to get all field names:

dm.TestClass.get_all_fields()

It would also work if the field names are assigned to an attribute. Just any way to make it make it more readable

I have tried using `__post_init__` or `__init__` - but pydantic seems to have a mind of its own — 5th, Feb 19 '22 at 14:15

score 2 · Accepted Answer · answered Feb 19 '22 at 15:55

Okay the solution is to use a class-method instead of an instance method:

from pydantic import BaseModel, Field

class AdaptedModel(BaseModel):
    @classmethod
    def get_field_names(cls,alias=False):
        return list(cls.schema(alias).get("properties").keys())

class TestClass(AdaptedModel):
    test: str = Field(alias="TEST")

We are using Python 3.6.8 and apparently it was already introduce. For completeness sake can somebody comment since when @classmethod exists? I assume since 3.6.

score 0 · Answer 2 · answered Jun 02 '22 at 18:24

What about just using __fields__:

from pydantic import BaseModel

class AdaptedModel(BaseModel):
    parent_attr: str

class TestClass(AdaptedModel):
    child_attr: str
        
TestClass.__fields__

Output:

{'parent_attr': ModelField(name='parent_attr', type=str, required=True),
 'child_attr': ModelField(name='child_attr', type=str, required=True)}

This is just a dict and you could get only the field names simply by: TestClass.__fields__.keys()

See model properties: https://pydantic-docs.helpmanual.io/usage/models/#model-properties

Short way to get all field names of a pydantic class

2 Answers2