FastAPI · interview question
What does a strong engineer do when reasoning through validation code?
Multiple choiceMediumchapter-13-curatedpremiumfastapivalidation
class CreateOrderRequest(BaseModel):
sku: str
quantity: int
@field_validator("quantity")
@classmethod
def quantity_must_be_positive(cls, value: int) -> int:
if value <= 0:
raise ValueError("quantity must be positive")
return valueAnswer and explanation
Correct answer
D. Narrate the data shape, the state changes, and the exact rule order step by step.
Why
Interviewers often use simple code to test whether you can reason through execution without bluffing.
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