What are Pydantic models and how do I use them?

What are Pydantic models and how do I use them?

Pydantic models are data validation and settings management tools in Python. They allow you to define data structures with type annotations and validate data automatically.

Can you show me a simple example of a Pydantic model?

Sure! Here's a basic example:

from pydantic import BaseModel

class User(BaseModel):
    id: int
    name: str
    email: str

This defines a User model with three fields: id, name, and email.

How do I validate data using this model?

You can create an instance of the model with the data you want to validate. If the data is invalid, Pydantic will raise a validation error. For example:

user = User(id=1, name='John Doe', email='[email protected]')  # Valid
user = User(id='not-an-int', name='John Doe', email='[email protected]')  # Raises ValidationError

What if I want to add default values to the fields?

You can specify default values directly in the model definition. For example:

class User(BaseModel):
    id: int = 0
    name: str = 'Unknown'
    email: str = '[email protected]'