How do I use Pydantic for data validation in Python?

What is Pydantic and how can I use it for data validation?

Pydantic is a data validation and settings management library for Python. It uses Python type annotations to validate data and ensure it meets specified types.

Can you show me a simple example of how to use Pydantic?

Sure! Here's a basic example:

from pydantic import BaseModel

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

user = User(id=1, name='John Doe', email='[email protected]')
print(user)

This will create a User object with validated fields.

What happens if I provide invalid data?

If you provide invalid data, Pydantic will raise a ValidationError. For example, if you pass a string instead of an integer for the id, it will notify you of the type mismatch.

How can I customize validation rules in Pydantic?

You can customize validation by using validators. For example, you can define a method decorated with @validator to enforce specific rules on your fields.