Add PairCandleMissing exception

tradingstrategy/pair.py

@@ -771,6 +771,7 @@ def __init__(self,
 
         self.exchange_universe = exchange_universe
 
+        #: A hack used in a single trading pair univerwse
         self.single_pair_cache: DEXPair = None
 
     def iterate_pairs(self) -> Iterable[DEXPair]:
@@ -2292,4 +2293,9 @@ def _convert_to_dex_pair(data: dict, exchange_universe: ExchangeUniverse | None=
     except Exception as e:
         pretty = pprint.pformat(data)
         raise DataDecodeFailed(f"Could not decode trading pair data:\n{pretty}") from e
-    return obj
+    return obj
+
+
+
+
+

tradingstrategy/utils/groupeduniverse.py

@@ -37,6 +37,10 @@ class NoDataAvailable(Exception):
     """Raises when the user is asking data that is empty."""
 
 
+class PairCandlesMissing(KeyError):
+    """Raises when the user is asking data for a pair that has no OHLCV feed."""
+
+
 class PairGroupedUniverse:
     """A base class for manipulating columnar price/liquidity data by a pair.
 
@@ -177,7 +181,7 @@ def get_samples_by_pair(self, pair_id: PrimaryKey) -> pd.DataFrame:
         try:
             pair = self.pairs.get_group(pair_id)
         except KeyError as e:
-            raise KeyError(f"No OHLC samples for pair id {pair_id} in {self}") from e
+            raise PairCandlesMissing(f"No OHLC samples for pair id {pair_id} in {self}") from e
         return pair
 
     def get_last_entries_by_pair_and_timestamp(self,