1. Data Validation through Python Type Hints

Pydantic uses Python’s type hints to validate data automatically when creating objects.

from pydantic import BaseModel

class Order(BaseModel):
    user_id: int
    product_id: int
    quantity: int

order = Order(user_id=101, product_id=502, quantity=2)
print(order)

2. Automatic Parsing and Serialization

from pydantic import BaseModel
from datetime import datetime

class Booking(BaseModel):
    event_name: str
    event_date: datetime

booking = Booking(event_name="Music Concert", event_date="2025-03-15T19:30:00")
print(booking.json())

3. Custom Validators

from pydantic import BaseModel, EmailStr, validator

class User(BaseModel):
    email: EmailStr
    @validator('email')
    def validate_email_domain(cls, v):
        if not v.endswith('@example.com'):
            raise ValueError('Email must be from example.com domain')
        return v

4. JSON Schema Generation

from pydantic import BaseModel

class Product(BaseModel):
    id: int
    name: str
    price: float

print(Product.schema_json())

5. Environment Variable Management

from pydantic import BaseSettings

class Config(BaseSettings):
    database_url: str
    secret_key: str

    class Config:
        env_file = '.env'

config = Config()
print(config.database_url)