Menene ƙananan Pydantic a FastAPI?

Question

Accepted Answer

**Ƙananan Pydantic** wajen aji (subclassing `BaseModel`) da suke bayyana **tsarin, nau'i, da ƙaidodin ingantawa** na bayanai. FastAPI suna amfani da su a ko'ina — don jiki na bukatun, siffofi na amsa, da saittuna — yana sa su zaka na ƙirki ɓangaren nau'i.

## Ƙira ƙananan

```python
from pydantic import BaseModel, EmailStr, Field

class User(BaseModel):
    name: str
    email: EmailStr                          # validates email format
    age: int = Field(ge=0, le=120)            # constraint: 0 <= age <= 120
    is_active: bool = True                    # default value
    tags: list[str] = []                      # typed list with a default
```

Kowana filin yana tanadi nau'i da karɓuwa/tsohuwar bukatai na zaɓe. Pydantic yana inganta bayanai a kaɓin wannan ma'anar kuma yana jujjuyar nau'i inda ya zo daidai.

## Nuni da aikin ingantawa na atomatik

```python
@app.post("/users")
def create_user(user: User):                  # FastAPI builds & validates a User from the body
    return user                               # already validated here
# valid JSON → a typed User object; invalid → automatic 422 with field-level errors
```

Idan aka yi amfani da shi azaman nau'in sigar, FastAPI za ta tuba jikin bukatun JSON a cikin ƙananan, **inganta** kowane filin kuma mayar da kuskure na tsarin 422 da zaa ta jera abin da yake rashin haɗi daidai — duka atomatik.

## Abinda Pydantic ke ba ku

```text
✓ Validation — type checks + constraints (lengths, ranges, formats), clear errors
✓ Parsing/coercion — "5" → 5, ISO string → datetime, etc.
✓ Serialization — model.model_dump() / model_dump_json() → dict/JSON
✓ Editor support — full autocomplete & type checking on model attributes
✓ Self-documenting — the model defines the schema used in the auto-generated docs
```

## Tushen gida gida na karya

```text
One Pydantic model drives: request validation, the response schema, the OpenAPI docs,
and typed access in your code → define the data shape ONCE.
```

## Me yasa yamatsa

Ƙananan Pydantic ne gidaje na FastAPI — wannan shine yadda kake bayyana kuma kake inganta bayanai da bukatun yaɗu yi amfani da kuma koma da shi, kuma kusan kowane halin FastAPI yana wucewar su.

Ganin su ya zama mahimmanci ne saboda suke ba da ingantawa **atomatik** (mahimmanci ga baje da ƙarawa — koda time ba kaidon bayanai), nuni/tilaɓi, ajiyar bayanai, da goyon bayan editon, duka daga wata ajiya ƙunshe da ilani.

Suna aiki azaman **tushen gida gida na karya** : ƙananan daya ke tukowa kaɓin ingantawa, siffa na amsa, kuma takaita da aka kirkira atomatik.

Wannan nau'i-tukowa, inganta da tsohuwa- don ka baje da shirye-shirye — samun ingantawa ƙarawa kuma saƙo na kuskure a sarari — babbar dalili ce FastAPI ce masu aiki da aminci, yana sa ƙananan Pydantic zama ilimi na mahimmanci, dole ne a kumata.