Update instruments.py (#192)

* Update instruments.py

get_chain now returns a list with all chains

* compact formatting

---------

Co-authored-by: Graeme Holliday <[email protected]>

Author: Quenos

tastytrade/instruments.py

@@ -660,7 +660,7 @@ class NestedOptionChain(TastytradeJsonDataclass):
     expirations: list[NestedOptionChainExpiration]
 
     @classmethod
-    async def a_get_chain(cls, session: Session, symbol: str) -> Self:
+    async def a_get_chain(cls, session: Session, symbol: str) -> list[Self]:
         """
         Gets the option chain for the given symbol in nested format.
 
@@ -669,10 +669,10 @@ async def a_get_chain(cls, session: Session, symbol: str) -> Self:
         """
         symbol = symbol.replace("/", "%2F")
         data = await session._a_get(f"/option-chains/{symbol}/nested")
-        return cls(**data["items"][0])
+        return [cls(**item) for item in data["items"]]
 
     @classmethod
-    def get_chain(cls, session: Session, symbol: str) -> Self:
+    def get_chain(cls, session: Session, symbol: str) -> list[Self]:
         """
         Gets the option chain for the given symbol in nested format.
 
@@ -681,7 +681,7 @@ def get_chain(cls, session: Session, symbol: str) -> Self:
         """
         symbol = symbol.replace("/", "%2F")
         data = session._get(f"/option-chains/{symbol}/nested")
-        return cls(**data["items"][0])
+        return [cls(**item) for item in data["items"]]
 
 
 class FutureProduct(TastytradeJsonDataclass):