modify exception message hint for storage.py && fix FileFeatureStorag…

…e[:] bug

qlib/data/data.py

@@ -663,7 +663,7 @@ def feature(self, instrument, field, start_index, end_index, freq):
             data = self.backend_obj(instrument=instrument, field=field, freq=freq)[start_index : end_index + 1]
         except Exception as e:
             get_module_logger("data").warning(
-                f"WARN: data not found for {instrument}.{field}\n\tException info: {str(e)}"
+                f"WARN: data not found for {instrument}.{field}\n\tFeature exception info: {str(e)}"
             )
             data = pd.Series(dtype=np.float32)
         return data

qlib/data/storage/file_storage.py

@@ -230,20 +230,19 @@ def __getitem__(self, i: Union[int, slice]) -> Union[Tuple[int, float], pd.Serie
                 raise TypeError(f"type(i) = {type(i)}")
 
         with open(self.uri, "rb") as fp:
-            ref_start_index = int(np.frombuffer(fp.read(4), dtype="<f")[0])
 
             if isinstance(i, int):
-                if ref_start_index > i:
-                    raise IndexError(f"{i}: start index is {ref_start_index}")
-                fp.seek(4 * (i - ref_start_index) + 4)
+                if self.start_index > i:
+                    raise IndexError(f"{i}: start index is {self.start_index}")
+                fp.seek(4 * (i - self.start_index) + 4)
                 return i, struct.unpack("f", fp.read(4))[0]
             elif isinstance(i, slice):
-                start_index = i.start
-                end_index = i.stop - 1
-                si = max(ref_start_index, start_index)
+                start_index = self.start_index if i.start is None else i.start
+                end_index = self.end_index if i.stop is None else i.stop - 1
+                si = max(self.start_index, start_index)
                 if si > end_index:
                     return pd.Series()
-                fp.seek(4 * (si - ref_start_index) + 4)
+                fp.seek(4 * (si - self.start_index) + 4)
                 # read n bytes
                 count = end_index - si + 1
                 data = np.frombuffer(fp.read(4 * count), dtype="<f")

qlib/data/storage/storage.py

@@ -53,10 +53,12 @@ def __new__(cls, name, bases, dict):
         _getitem_func = getattr(class_obj, "__getitem__")
 
         def _getitem(obj, item):
-            _check_func = getattr(obj, "_check")
-            if callable(_check_func):
-                _check_func()
-            return _getitem_func(obj, item)
+            getattr(obj, "_check")()
+            try:
+                res = _getitem_func(obj, item)
+            except Exception as e:
+                raise ValueError(f"{obj.raise_info}\n\tStorage exception info: {str(e)}")
+            return res
 
         setattr(class_obj, "__getitem__", _getitem)
         return class_obj
@@ -65,7 +67,16 @@ def _getitem(obj, item):
 class BaseStorage(metaclass=StorageMeta):
     @property
     def storage_name(self) -> str:
-        return re.findall("[A-Z][^A-Z]*", self.__class__.__name__)[-2]
+        return re.findall("[A-Z][^A-Z]*", self.__class__.__name__)[-2].lower()
+
+    @property
+    def raise_info(self):
+        parameters_info = [
+            f"{_k}={_v}"
+            for _k, _v in self.__dict__.items()
+            if not isinstance(_v, (dict,)) or (hasattr(_v, "__len__") and len(_v) < 3)
+        ]
+        return f"{self.storage_name.lower()} not exists, storage parameters: {parameters_info}"
 
     def check_exists(self) -> bool:
         """check if storage(uri) exists, if not exists: return False"""
@@ -84,15 +95,17 @@ def __getitem__(self, item: Union[slice, Union[int, InstKT]]):
         )
 
     def _check(self):
-        # check storage(uri)
         if not self.check_exists():
-            parameters_info = [f"{_k}={_v}" for _k, _v in self.__dict__.items()]
-            raise ValueError(f"{self.storage_name.lower()} not exists, storage parameters: {parameters_info}")
+            raise ValueError(self.raise_info)
 
     def __getattribute__(self, item):
         if item == "data":
             self._check()
-        return super(BaseStorage, self).__getattribute__(item)
+        try:
+            res = super(BaseStorage, self).__getattribute__(item)
+        except Exception as e:
+            raise ValueError(f"{self.raise_info}\n\tStorage exception info: {str(e)}")
+        return res
 
 
 class CalendarStorage(BaseStorage):

tests/storage_tests/test_storage.py

@@ -135,18 +135,12 @@ def test_feature_storage(self):
 
         feature = FeatureStorage(instrument="SH600004", field="close", freq="day", uri=self.provider_uri)
 
-        with pytest.raises(IndexError):
+        with pytest.raises(ValueError):
             print(feature[0])
         assert isinstance(
             feature[815][1], (float, np.float32)
         ), f"{feature.__class__.__name__}.__getitem__(i: int) error"
         assert len(feature[815:818]) == 3, f"{feature.__class__.__name__}.__getitem__(s: slice) error"
-        print(f"feature[815: 818]: {feature[815: 818]}")
-
-        for _item in feature:
-            assert (
-                isinstance(_item, tuple) and len(_item) == 2
-            ), f"{feature.__class__.__name__}.__iter__ item type error"
-            assert isinstance(_item[0], int) and isinstance(
-                _item[1], (float, np.float32)
-            ), f"{feature.__class__.__name__}.__iter__ value type error"
+        print(f"feature[815: 818]: \n{feature[815: 818]}")
+
+        print(f"feature[:].tail(): \n{feature[:].tail()}")