from pydantic import BaseModel, Field

# Base Schema
class SeaLionBase(BaseModel):
    name: str = Field(..., description="Name of the sea lion")
    species: str = Field(..., description="Species of the sea lion")
    age: int | None = Field(None, description="Age of the sea lion")
    weight: float | None = Field(None, description="Weight of the sea lion")
    location: str = Field(..., description="Location of the sea lion")

    class Config:
        schema_extra = {
            "example": {
                "name": "Buddy",
                "species": "California Sea Lion",
                "age": 5,
                "weight": 200.5,
                "location": "Pacific Ocean"
            }
        }

# Schema for Create Operation
class SeaLionCreate(SeaLionBase):
    pass

# Schema for Response
class SeaLion(SeaLionBase):
    id: int = Field(..., description="Unique identifier for the sea lion")

    class Config:
        schema_extra = {
            "example": {
                "id": 1,
                "name": "Buddy",
                "species": "California Sea Lion",
                "age": 5,
                "weight": 200.5,
                "location": "Pacific Ocean"
            }
        }
```

This code defines three Pydantic models for the SeaLion entity:

1. `SeaLionBase`: A base model that defines the common fields for the entity.
2. `SeaLionCreate`: A model that inherits from `SeaLionBase` and is used for creating new sea lion instances.
3. `SeaLion`: A model that inherits from `SeaLionBase` and includes an `id` field, which is used for representing sea lion instances in API responses.

Each model includes field descriptions and example values in the `Config` class. The `SeaLion` model also includes an example value for the `id` field.