Pydantic models

Pydantic validates and parses data into Python objects—ideal for JSON bodies once you reach the web chapters. The examples below stay small so you can focus on syntax and validation first.

Install locally if needed (your template may already include it):

pip install pydantic

BaseModel and fields

from pydantic import BaseModel, Field

class ListenerHeader(BaseModel):
    name: str
    port: int
    enabled: bool = Field(default=True)

class ListenerOptions(BaseModel):
    use_ssl: bool = Field(default=False)
    jitter: int = Field(default=1)
    port: int = Field(default=4444)

• Required fields have no default.
• Field(default=...) sets defaults and can carry validation rules (min, max, regex, …).

Creating and reading instances

h = ListenerHeader(name="alpha", port=8080)
print(h.name, h.port, h.enabled)  # enabled defaults True

Enum and StrEnum (optional)

Enumerations restrict values to a fixed set:

from enum import Enum

class Status(Enum):
    pending = "pending"
    done = "done"

StrEnum (Python 3.11+) makes members strings as well—handy for JSON.

Implement

1. Define BaseModel classes for something simple (e.g. User with username, age with default Field constraints if your rubric asks).
2. Instantiate from literals, then print a field.
3. Commit and push.