Add Planet schema

schemas/planet.py

@@ -0,0 +1,50 @@
+from pydantic import BaseModel, Field
+
+# Base Schema
+class PlanetBase(BaseModel):
+    name: str = Field(..., description="Name of the planet")
+    description: str | None = Field(None, description="Description of the planet")
+    diameter: int = Field(..., gt=0, description="Diameter of the planet in kilometers")
+    mass: int = Field(..., gt=0, description="Mass of the planet in kilograms")
+    distance_from_sun: int = Field(..., gt=0, description="Distance from the sun in kilometers")
+
+# Schema for creating a new Planet
+class PlanetCreate(PlanetBase):
+    pass
+
+    class Config:
+        schema_extra = {
+            "example": {
+                "name": "Earth",
+                "description": "The planet we live on",
+                "diameter": 12742,
+                "mass": 5972000000000000000000000,
+                "distance_from_sun": 149600000
+            }
+        }
+
+# Schema for Planet responses
+class Planet(PlanetBase):
+    id: int
+
+    class Config:
+        orm_mode = True
+        schema_extra = {
+            "example": {
+                "id": 1,
+                "name": "Earth",
+                "description": "The planet we live on",
+                "diameter": 12742,
+                "mass": 5972000000000000000000000,
+                "distance_from_sun": 149600000
+            }
+        }
+```
+
+This code defines three Pydantic schemas for the Planet entity:
+
+1. `PlanetBase`: A base schema that defines the common fields for a planet.
+2. `PlanetCreate`: A schema for creating a new planet, inheriting from `PlanetBase`. It includes an example configuration for request validation.
+3. `Planet`: A schema for planet responses, inheriting from `PlanetBase` and adding an `id` field. It includes an example configuration and sets `orm_mode=True` for compatibility with ORMs like SQLAlchemy.
+
+The schemas use appropriate Pydantic field types and include validation rules using `Field()`. The `description` field is marked as nullable (`None`), while other fields are required. The `gt=0` validation ensures that numeric fields are positive.