[FIXED] How to filter out NaN by pydantic

Issue

How to filter out NaN in pytdantic float validation?

from pydantic import BaseModel

class MySchema(BaseModel):
    float_value: float

Solution

You can use confloat and set either the higher limit to infinity or the lower limit to minus infinity. As all numeric comparisons with NaN return False, that will make pydantic reject NaN, while leaving all other behaviour identical (including parsing, conversion from int to float, ...).

from pydantic import BaseModel, confloat

class MySchema(BaseModel):
    float_value: confloat(ge=-float('inf'))
    # or:
    # float_value: confloat(le=float('inf'))

Note: you could additionally exclude infinity values by using the gt and lt arguments of confloat instead of ge and le.

Testing:

m = MySchema(float_value=float('nan'))

Output:

pydantic.error_wrappers.ValidationError: 1 validation error for MySchema
float_value
  ensure this value is greater than or equal to -inf (type=value_error.number.not_ge; limit_value=-inf)

Answered By - ye olde noobe