python type_error ai_generated true

fastapi.exceptions.RequestValidationError: field required

ID: python/fastapi-validation-error-field-required

Also available as: JSON · Markdown · 中文
80%Fix Rate
87%Confidence
0Evidence
2024-04-12First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
3.x active — — —

Root Cause

A required field in the request body or query parameters is missing.

generic

中文

请求体或查询参数中缺少必填字段。

Workarounds

  1. 90% success Add default values or make fields optional 
    class Item(BaseModel):
    name: str = 'default'  # optional with default
    price: float = 0.0
  2. 85% success Use Pydantic's Field with alias 
    class Item(BaseModel):
    item_name: str = Field(..., alias='name')
# Request uses 'name', model uses 'item_name'

Dead Ends

Common approaches that don't work:

  1. Providing field with None value 70% fail

    FastAPI treats None as missing for required fields.

  2. Using wrong field name due to case sensitivity 60% fail

    Field names are case-sensitive in Pydantic models.