Make data-finding safe

freqtrade/data/datahandlers/jsondatahandler.py

@@ -19,8 +19,11 @@ def ohlcv_get_pairs(cls, datadir: Path, timeframe: str) -> List[str]:
         """
         Returns a list of all pairs available in this datadir
         """
-        return [re.search(r'^(\S+)(?=\-' + timeframe + '.json)', p.name)[0].replace('_', ' /')
+
+        _tmp = [re.search(r'^(\S+)(?=\-' + timeframe + '.json)', p.name)
                 for p in datadir.glob(f"*{timeframe}.{cls._get_file_extension()}")]
+        # Check if regex found something and only return these results
+        return [match[0].replace('_', ' /') for match in _tmp if match]
 
     def ohlcv_store(self, timeframe: str, data: DataFrame):
         """
@@ -54,8 +57,10 @@ def trades_get_pairs(cls, datadir: Path) -> List[str]:
         """
         Returns a list of all pairs available in this datadir
         """
-        return [re.search(r'^(\S+)(?=\-trades.json)', p.name)[0].replace('_', '/')
+        _tmp = [re.search(r'^(\S+)(?=\-trades.json)', p.name)
                 for p in datadir.glob(f"*trades.{cls._get_file_extension()}")]
+        # Check if regex found something and only return these results to avoid exceptions.
+        return [match[0].replace('_', ' /') for match in _tmp if match]
 
     def trades_store(self, data: List[Dict]):
         """