Complete 2nd class: Path parameters w/Type hints

Added a comment for one block, wondering why we should use `next` instead of a the `get` method for a dictionary

main.py

@@ -1,16 +1,46 @@
-from fastapi import FastAPI
+from enum import Enum
+from fastapi import FastAPI, HTTPException
 
 # use localhost:{port} in browser
 # use localhost:{port}/docs to look at the interactive, automatically created documentation
 
 app = FastAPI()
 
 
-@app.get("/")
-async def index() -> dict[str, str]:
-    return {"hello": "world"}
+class GenreURLChoices(Enum):
+    ROCK = "rock"
+    ELECTRONIC = "electronic"
+    METAL = "metal"
+    HIP_HOP = "hip-hop"
+    SHOEGAZE = "shoegaze"
 
 
-@app.get("/about")
-async def about() -> str:
-    return "About MeaLeon"
+BANDS = [
+    {"id": 1, "name": "The Kinks", "genre": "Rock"},
+    {"id": 2, "name": "Aphex Twin", "genre": "Electronic"},
+    {"id": 3, "name": "Slowdive", "genre": "Shoegaze"},
+    {"id": 4, "name": "Wu-Tang Clan", "genre": "Hip-Hop"},
+    {"id": 5, "name": "Black Sabbath", "genre": "Metal"},
+]
+
+
+@app.get("/bands")
+async def bands() -> list[dict]:
+    return BANDS
+
+
+@app.get("/bands/{band_id}")
+async def band(band_id: int) -> dict:
+    band = next((b for b in BANDS if b["id"] == band_id), None)
+    # Aaron: I'm a little confused, could we use `get` instead?
+
+    if band is None:
+        # status code 404
+        raise HTTPException(status_code=404, detail="Band not found")
+    return band
+
+
+@app.get("/bands/genre/{genre}")
+async def bands_for_genre(genre: GenreURLChoices) -> list[dict]:
+    # originally this allowed any string to be used as an input and a list comprehension was used to find the value. However, this could result in server/computer waste, so we refactored to use a custom class that was restricted to a known set of genres
+    return [b for b in BANDS if b["genre"].lower() == genre.value]