Pydantic: How do I use a keyword field name?

Question

I'm trying to model an API request in Pydantic. I have to model a field called "from". Since "from" is a keyword in python, Pydantic throws an error.

Model

class MyRequest(BaseModel):
    foo: str
    abc: int
    from: int

Error thrown by Pydantic

File "test.py", line 6
    from: int

SyntaxError: invalid syntax

Is there to model this "from" field? Changing the parameter name is not an option.

my be because 'from' key word in python change it and see – hamza chenni Dec 20 '20 at 18:07 — hamza chenni, Dec 20 '20 at 18:07

score 20 · Answer 1 · answered Mar 10 '20 at 16:25

20

Use an alias:

class MyRequest(BaseModel):
    foo: str
    abc: int
    from_field: int = Field(..., alias='from')

answered Mar 10 '20 at 16:25

SColvin

1

how should it be instantiated? `MyRequest(foo='a', abc=1, from=2)` still raises a `SyntaxError`, while using `from_field` instead of `from` will lead to a `pydantic.ValidationError`. – Algebra8 Mar 09 '21 at 23:21
4

Have you tried `MyRequest(**{'foo': 'a', 'abc': 1, 'from': 2})`? – SColvin Mar 10 '21 at 16:37

1 Answers1