add highfreq example

examples/high_freq/highfreq_handler.py

@@ -0,0 +1,220 @@
+from qlib.data.dataset.handler import DataHandler, DataHandlerLP
+from qlib.data.dataset.processor import Processor
+from qlib.utils import get_cls_kwargs
+from qlib.log import TimeInspector
+
+
+class HighFreqHandler(DataHandlerLP):
+    def __init__(
+        self,
+        instruments="csi500",
+        start_time=None,
+        end_time=None,
+        freq="1min",
+        infer_processors=[],
+        learn_processors=[],
+        fit_start_time=None,
+        fit_end_time=None,
+        drop_raw=True,
+    ):
+        def check_transform_proc(proc_l):
+            new_l = []
+            for p in proc_l:
+                p["kwargs"].update(
+                    {
+                        "fit_start_time": fit_start_time,
+                        "fit_end_time": fit_end_time,
+                    }
+                )
+                new_l.append(p)
+            return new_l
+
+        infer_processors = []
+        learn_processors = []
+
+        data_loader = {
+            "class": "QlibDataLoader",
+            "kwargs": {
+                "config": self.get_feature_config(),
+                "swap_level": False,
+            },
+        }
+        super().__init__(
+            instruments=instruments,
+            start_time=start_time,
+            end_time=end_time,
+            freq=freq,
+            data_loader=data_loader,
+            infer_processors=infer_processors,
+            learn_processors=learn_processors,
+            drop_raw=drop_raw,
+        )
+
+
+    def get_feature_config(self):
+        fields = []
+        names = []
+
+        template_if = "If(IsNull({1}), {0}, {1})"
+        template_paused = "Select(Eq($paused, 0.0), {0})"
+        template_fillnan = "FFillNan({0})"
+        fields += [
+            "{0}/Ref(DayLast({1}), 240)".format(
+                template_if.format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$open"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        fields += [
+            "{0}/Ref(DayLast({1}), 240)".format(
+                template_if.format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$high"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        fields += [
+            "{0}/Ref(DayLast({1}), 240)".format(
+                template_if.format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$low"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        fields += ["{0}/Ref(DayLast({0}), 240)".format(template_fillnan.format(template_paused.format("$close")))]
+        fields += [
+            "{0}/Ref(DayLast({1}), 240)".format(
+                "If(IsNull({1}), {0}, If(Or(Or(Or(Eq({1}, np.inf), Eq({1}, -np.inf)), Eq({1}, 0)), Or(Gt({1}, Mul(1.001, {3})), Lt({1}, Mul(0.999, {2})))), {0}, {1}))".format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$vwap"),
+                    template_paused.format("$low"),
+                    template_paused.format("$high"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        names += ["$open", "$high", "$low", "$close", "$vwap"]
+        
+        fields += [
+            "Ref({0}, 240)/Ref(DayLast({1}), 240)".format(
+                template_if.format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$open"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        fields += [
+            "Ref({0}, 240)/Ref(DayLast({1}), 240)".format(
+                template_if.format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$high"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        fields += [
+            "Ref({0}, 240)/Ref(DayLast({1}), 240)".format(
+                template_if.format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$low"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        fields += [
+            "Ref({0}, 240)/Ref(DayLast({0}), 240)".format(template_fillnan.format(template_paused.format("$close")))
+        ]
+        fields += [
+            "Ref({0}, 240)/Ref(DayLast({1}), 240)".format(
+                "If(IsNull({1}), {0}, If(Or(Or(Or(Eq({1}, np.inf), Eq({1}, -np.inf)), Eq({1}, 0)), Or(Gt({1}, Mul(1.001, {3})), Lt({1}, Mul(0.999, {2})))), {0}, {1}))".format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$vwap"),
+                    template_paused.format("$low"),
+                    template_paused.format("$high"),
+                ),
+                template_fillnan.format(template_paused.format("$close")),
+            )
+        ]
+        names += ["$open_1", "$high_1", "$low_1", "$close_1", "$vwap_1"]
+
+        fields += [
+            "{0}/Ref(DayLast(Mean({0}, 7200)), 240)".format(
+                "If(IsNull({1}), 0, If(Or(Gt({2}, Mul(1.001, {4})), Lt({2}, Mul(0.999, {3}))), 0, {1}))".format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$volume"),
+                    template_paused.format("$vwap"),
+                    template_paused.format("$low"),
+                    template_paused.format("$high"),
+                )
+            )
+        ]
+        names += ["$volume"]
+        fields += [
+            "Ref({0}, 240)/Ref(DayLast(Mean({0}, 7200)), 240)".format(
+                "If(IsNull({1}), 0, If(Or(Gt({2}, Mul(1.001, {4})), Lt({2}, Mul(0.999, {3}))), 0, {1}))".format(
+                    template_fillnan.format(template_paused.format("$close")),
+                    template_paused.format("$volume"),
+                    template_paused.format("$vwap"),
+                    template_paused.format("$low"),
+                    template_paused.format("$high"),
+                )
+            )
+        ]
+        names += ["$volume_1"]
+
+        fields += [template_paused.format("Date($close)")]
+        names += ["date"]
+        return fields, names
+
+
+class HighFreqBacktestHandler(DataHandler):
+    def __init__(
+        self,
+        instruments="csi300",
+        start_time=None,
+        end_time=None,
+        freq="1min",
+    ):
+        infer_processors = check_transform_proc(infer_processors)
+        learn_processors = check_transform_proc(learn_processors)
+        data_loader = {
+            "class": "QlibDataLoader",
+            "kwargs": {
+                "config": self.get_feature_config(),
+                "swap_level": False,
+            },
+        }
+        super().__init__(
+            instruments=instruments,
+            start_time=start_time,
+            end_time=end_time,
+            freq=freq,
+            data_loader=data_loader,
+        )
+
+    def get_feature_config(self):
+        fields = []
+        names = []
+
+        template_if = "If(Eq({1}, np.nan), {0}, {1})"
+        template_paused = "Select(Eq($paused, 0.0), {0})"
+        template_fillnan = "FFillNan({0})"
+
+        fields += [template_fillnan.format(template_paused.format("$close")),]
+        names += ["$close0"]
+        fields += [
+            "If(Eq({1}, np.nan), 0, If(Or(Gt({2}, Mul(1.001, {4})), Lt({2}, Mul(0.999, {3}))), 0, {1}))".format(
+                template_fillnan.format(template_paused.format("$close")),
+                template_paused.format("$volume"),
+                template_paused.format("$vwap"),
+                template_paused.format("$low"),
+                template_paused.format("$high"),
+            )
+        ]
+        names += ["$volume0"]
+        return fields, names

examples/high_freq/highfreq_ops.py

@@ -0,0 +1,62 @@
+import numpy as np
+import pandas as pd
+import importlib
+from qlib.data.ops import ElemOperator, PairOperator
+from qlib.config import C
+from qlib.data.data import Cal
+
+
+class DayFirst(ElemOperator):
+    def __init__(self, feature):
+        super(DayFirst, self).__init__(feature, "day_first")
+    
+    def _load_internal(self, instrument, start_index, end_index, freq):
+        _calendar = Cal.get_calender_day(freq=freq)[0]
+        series = self.feature.load(instrument, start_index, end_index, freq)
+        return series.groupby(_calendar[series.index]).transform("first")
+
+
+class DayLast(ElemOperator):
+    def __init__(self, feature):
+        super(DayLast, self).__init__(feature, "day_last")
+
+    def _load_internal(self, instrument, start_index, end_index, freq):
+        _calendar = Cal.get_calender_day(freq=freq)[0]
+        series = self.feature.load(instrument, start_index, end_index, freq)
+        return series.groupby(_calendar[series.index]).transform("last")
+
+
+class FFillNan(ElemOperator):
+    def __init__(self, feature):
+        super(FFillNan, self).__init__(feature, "fill_nan")
+
+    def _load_internal(self, instrument, start_index, end_index, freq):
+        series = self.feature.load(instrument, start_index, end_index, freq)
+        return series.fillna(method="ffill")
+
+
+class Date(ElemOperator):
+    def __init__(self, feature):
+        super(Date, self).__init__(feature, "date")
+
+    def _load_internal(self, instrument, start_index, end_index, freq):
+        _calendar = Cal.get_calender_day(freq=freq)[0]
+        series = self.feature.load(instrument, start_index, end_index, freq)
+        return pd.Series(_calendar[series.index], index=series.index)
+
+class Select(PairOperator):
+    def __init__(self, condition, feature):
+        super(Select, self).__init__(condition, feature, "select")
+
+    def _load_internal(self, instrument, start_index, end_index, freq):
+        series_condition = self.feature_left.load(instrument, start_index, end_index, freq)
+        series_feature = self.feature_right.load(instrument, start_index, end_index, freq)
+        return series_feature.loc[series_condition]
+
+class IsNull(ElemOperator):
+    def __init__(self, feature):
+        super(IsNull, self).__init__(feature, "isnull")
+
+    def _load_internal(self, instrument, start_index, end_index, freq):
+        series = self.feature.load(instrument, start_index, end_index, freq)
+        return series.isnull()

examples/high_freq/highfreq_processor.py

@@ -0,0 +1,70 @@
+import numpy as np
+import pandas as pd
+from qlib.data.dataset.processor import Processor
+from qlib.log import TimeInspector
+from qlib.data.dataset.utils import fetch_df_by_index
+
+
+class HighFreqNorm(Processor):
+    def __init__(self, fit_start_time, fit_end_time):
+        self.fit_start_time = fit_start_time
+        self.fit_end_time = fit_end_time
+
+    def fit(self, df_features):
+        fetch_df = fetch_df_by_index(df, slice(self.fit_start_time, self.fit_end_time), level="datetime")
+        del df
+        df_values = fetch_df.values
+        names = {
+            "price": slice(0, 10),
+            "volume": slice(10, 12),
+        }
+        self.feature_med = {}
+        self.feature_std = {}
+        self.feature_vmax = {}
+        self.feature_vmin = {}
+        for name, name_val in names.items():
+            part_values = df_values[:, name_val]
+            if name == "volume":
+                df_features.loc(axis=1)[name_val] = np.log1p(part_values)
+            self.feature_med[name] = np.nanmedian(part_values)
+            part_values = part_values - self.feature_med  # mean, copy
+            self.feature_std[name] = np.nanmedian(np.absolute(part_values)) * 1.4826 + 1e-12
+            part_values = part_values / self.feature_std
+            self.feature_vmax[name] = np.nanmax(part_values)
+            self.feature_vmin[name] = np.nanmin(part_values)
+
+    def __call__(self, df_features):
+        df_features.set_index("date", append=True, drop=True, inplace=True)
+        df_values = df_features.values
+        names = {
+            "price": slice(0, 10),
+            "volume": slice(10, 12),
+        }
+
+        for name, name_val in names.items():
+            part_values = df_values[:, name_val]
+            if name == "volume":
+                part_values[:] = np.log1p(part_values)
+            part_values -= self.feature_med[name]
+            part_values /= self.feature_std[name]
+            slice0 = part_values > 3.0
+            slice1 = part_values > 3.5
+            slice2 = part_values < -3.0
+            slice3 = part_values < -3.5
+
+            part_values[slice0] = 3.0 + (part_values[slice0] - 3.0) / (self.feature_vmax[name] - 3) * 0.5
+            part_values[slice1] = 3.5
+            part_values[slice2] = -3.0 - (part_values[slice2] + 3.0) / (self.feature_vmin[name] + 3) * 0.5
+            part_values[slice3] = -3.5
+        # print("start_call_feature_reshape")
+        idx = df_features.index.droplevel("datetime").drop_duplicates()
+        feat = df_values[:, [0, 1, 2, 3, 4, 10]].reshape(-1, 6 * 240)
+        feat_1 = df_values[:, [5, 6, 7, 8, 9, 11]].reshape(-1, 6 * 240)
+
+        df_new_features = pd.DataFrame(
+           data=np.concatenate((feat, feat_1), axis=1),
+           index=idx,
+           columns=["FEATURE_%d" % i for i in range(12 * 240)],
+        ).sort_index()
+
+        return df_new_features

examples/high_freq/workflow.py

@@ -0,0 +1,137 @@
+#  Copyright (c) Microsoft Corporation.
+#  Licensed under the MIT License.
+
+import sys
+from pathlib import Path
+
+import qlib
+import pickle
+import numpy as np
+import pandas as pd
+from qlib.config import REG_CN
+from qlib.contrib.model.gbdt import LGBModel
+from qlib.contrib.data.handler import Alpha158
+from qlib.contrib.strategy.strategy import TopkDropoutStrategy
+from qlib.contrib.evaluate import (
+    backtest as normal_backtest,
+    risk_analysis,
+)
+
+from qlib.utils import init_instance_by_config
+from qlib.data.dataset.handler import DataHandlerLP
+from qlib.data.ops import Operators
+from qlib.data.data import Cal
+
+from highfreq_ops import DayFirst, DayLast, FFillNan, Date, Select, IsNull
+
+def save_dataset(dataset, path: [Path, str]):
+    """
+    save dataset to path
+
+    Parameters
+    ----------
+    path : [Path, str]
+        path to save
+    """
+    dataset.to_pickle(path=path)
+
+def load_dataset(path: [Path, str], init_type=DataHandlerLP.IT_LS):
+    """
+    load dataset from path
+
+    Parameters
+    ----------
+    path : [Path, str]
+        path to load
+
+    init_type : str
+        - if `init_type` == DataHandlerLP.IT_FIT_SEQ:
+
+            the input of `DataHandlerLP.fit` will be the output of the previous processor
+        
+        - if `init_type` == DataHandlerLP.IT_FIT_IND:
+
+            the input of `DataHandlerLP.fit` will be the original df
+
+        - if `init_type` == DataHandlerLP.IT_LS:
+
+            The state of the object has been load by pickle
+    """
+    fd = open(path, 'rb')
+    dataset = pickle.load(fd)
+    dataset.init(init_type=init_type)
+    fd.close()
+    return dataset
+
+if __name__ == "__main__":
+
+    # use default data
+    provider_uri = "/mnt/v-xiabi/data/qlib/high_freq"  # target_dir
+    qlib.init(provider_uri=provider_uri, custom_ops=[DayFirst, DayLast, FFillNan, Date, Select, IsNull], redis_port=233, region=REG_CN, auto_mount=False)
+
+    MARKET = "csi300"
+    BENCHMARK = "SH000300"
+
+    ###################################
+    # train model
+    ###################################
+    DATA_HANDLER_CONFIG0 = {
+        "start_time": "2017-01-01 00:00:00",
+        "end_time": "2020-11-30 15:00:00",
+        "freq": "1min",
+        "fit_start_time": "2017-01-01 00:00:00",
+        "fit_end_time": "2020-08-31 15:00:00",
+        "instruments": "all",
+        "infer_processors": [{"class": "HighFreqNorm", "module_path": "highfreq_processor", "kwargs": {}}],
+    }
+    DATA_HANDLER_CONFIG1 = {
+        "start_time": "2017-01-01 00:00:00",
+        "end_time": "2020-11-30 15:00:00",
+        "freq": "1min",
+        "instruments": "all",
+    }
+
+    task = {
+        "dataset": {
+            "class": "DatasetH",
+            "module_path": "qlib.data.dataset",
+            "kwargs": {
+                "handler": {
+                    "class": "HighFreqHandler",
+                    "module_path": "highfreq_handler",
+                    "kwargs": DATA_HANDLER_CONFIG0,
+                },
+                "segments": {
+                    "train": ("2017-01-01 00:00:00", "2020-08-31 15:00:00"),
+                    "test": (
+                        "2020-09-01 00:00:00",
+                        "2020-11-30 15:00:00",
+                    ),
+                },
+            },
+        },
+        # You shoud record the data in specific sequence
+        # "record": ['SignalRecord', 'SigAnaRecord', 'PortAnaRecord'],
+        "dataset_backtest": {
+            "class": "DatasetH",
+            "module_path": "qlib.data.dataset",
+            "kwargs": {
+                "handler": {
+                    "class": "HighFreqBacktestHandler",
+                    "module_path": "highfreq_hander",
+                    "kwargs": DATA_HANDLER_CONFIG1,
+                },
+                "segments": {
+                    "train": ("2017-01-01 00:00:00", "2020-08-31 15:00:00"),
+                    "test": (
+                        "2020-09-01 00:00:00",
+                        "2020-11-30 15:00:00",
+                    ),
+                },
+            },
+        },
+    }
+    Cal.get_calender_day(freq="1min")  # TO FIX: load the calendar day for cache
+    dataset = init_instance_by_config(task["dataset"])
+    dataset_backtest = init_instance_by_config(task["dataset_backtest"])
+

qlib/contrib/data/handler.py

@@ -49,6 +49,7 @@ class Alpha360(DataHandlerLP):
         instruments="csi500",
         start_time=None,
         end_time=None,
+        freq="day",
         infer_processors=_DEFAULT_INFER_PROCESSORS,
         learn_processors=_DEFAULT_LEARN_PROCESSORS,
         fit_start_time=None,
@@ -69,9 +70,10 @@ class Alpha360(DataHandlerLP):
         }
 
         super().__init__(
-            instruments,
+            instruments=instruments,
-            start_time,
+            start_time=start_time,
-            end_time,
+            end_time=end_time,
+            freq="day",
             data_loader=data_loader,
             learn_processors=learn_processors,
             infer_processors=infer_processors,
@@ -130,6 +132,7 @@ class Alpha158(DataHandlerLP):
         instruments="csi500",
         start_time=None,
         end_time=None,
+        freq="day",
         infer_processors=[],
         learn_processors=_DEFAULT_LEARN_PROCESSORS,
         fit_start_time=None,
@@ -147,9 +150,10 @@ class Alpha158(DataHandlerLP):
             },
         }
         super().__init__(
-            instruments,
+            instruments=instruments,
-            start_time,
+            start_time=start_time,
-            end_time,
+            end_time=end_time,
+            freq=freq,
             data_loader=data_loader,
             infer_processors=infer_processors,
             learn_processors=learn_processors,

qlib/data/data.py

@@ -123,6 +123,16 @@ class CalendarProvider(abc.ABC):
             H["c"][flag] = _calendar, _calendar_index
         return _calendar, _calendar_index
 
+    def get_calender_day(self, freq="day", future=False):
+        flag = f"{freq}_future_{future}_day"
+        if flag in H["c"]:
+            _calendar, _calendar_index = H["c"][flag]
+        else:
+            _calendar = np.array(list(map(lambda x: x.date(), self._load_calendar(freq, future))))
+            _calendar_index = {x: i for i, x in enumerate(_calendar)}  # for fast search
+            H["c"][flag] = _calendar, _calendar_index
+        return _calendar, _calendar_index
+        
     def _uri(self, start_time, end_time, freq, future=False):
         """Get the uri of calendar generation task."""
         return hash_args(start_time, end_time, freq, future)
@@ -686,7 +696,10 @@ class LocalExpressionProvider(ExpressionProvider):
         # 1) The stock data is currently float. If there is other types of data, this part needs to be re-implemented.
         # 2) The the precision should be configurable
         try:
-            series = series.astype(np.float32)
+            if series.dtype == np.float64:
+                series = series.astype(np.float32)
+            elif series.dtype == np.bool:
+                series = series.astype(np.int8)
         except ValueError:
             pass
         if not series.empty:

qlib/data/dataset/__init__.py

@@ -87,6 +87,36 @@ class DatasetH(Dataset):
         """
         super().__init__(handler, segments)
 
+
+    def init(self, init_type: str = DataHandlerLP.IT_FIT_SEQ, enable_cache: bool = False):
+        """
+        Initialize the data of Qlib
+
+        Parameters
+        ----------
+        init_type : str
+            - if `init_type` == DataHandlerLP.IT_FIT_SEQ:
+
+                the input of `DataHandlerLP.fit` will be the output of the previous processor
+            
+            - if `init_type` == DataHandlerLP.IT_FIT_IND:
+
+                the input of `DataHandlerLP.fit` will be the original df
+
+            - if `init_type` == DataHandlerLP.IT_LS:
+
+                The state of the object has been load by pickle
+
+        enable_cache : bool
+            default value is false:
+
+            - if `enable_cache` == True:
+
+                the processed data will be saved on disk, and handler will load the cached data from the disk directly
+                when we call `init` next time
+        """
+        self.handler.init(init_type=init_type, enable_cache=enable_cache)
+
     def setup_data(self, handler: Union[dict, DataHandler], segments: list):
         """
         Setup the underlying data.
@@ -116,8 +146,8 @@ class DatasetH(Dataset):
                         'outsample': ("2017-01-01", "2020-08-01",),
                     }
         """
-        self._handler = init_instance_by_config(handler, accept_types=DataHandler)
+        self.handler = init_instance_by_config(handler, accept_types=DataHandler)
-        self._segments = segments.copy()
+        self.segments = segments.copy()
 
     def _prepare_seg(self, slc: slice, **kwargs):
         """
@@ -127,7 +157,7 @@ class DatasetH(Dataset):
         ----------
         slc : slice
         """
-        return self._handler.fetch(slc, **kwargs)
+        return self.handler.fetch(slc, **kwargs)
 
     def prepare(
         self,
@@ -150,7 +180,7 @@ class DatasetH(Dataset):
             - ['train', 'valid']
 
         col_set : str
-            The col_set will be passed to self._handler when fetching data.
+            The col_set will be passed to self.handler when fetching data.
         data_key : str
             The data to fetch:  DK_*
             Default is DK_I, which indicate fetching data for **inference**.
@@ -166,16 +196,16 @@ class DatasetH(Dataset):
         logger = get_module_logger("DatasetH")
         fetch_kwargs = {"col_set": col_set}
         fetch_kwargs.update(kwargs)
-        if "data_key" in getfullargspec(self._handler.fetch).args:
+        if "data_key" in getfullargspec(self.handler.fetch).args:
             fetch_kwargs["data_key"] = data_key
         else:
             logger.info(f"data_key[{data_key}] is ignored.")
 
         # Handle all kinds of segments format
         if isinstance(segments, (list, tuple)):
-            return [self._prepare_seg(slice(*self._segments[seg]), **fetch_kwargs) for seg in segments]
+            return [self._prepare_seg(slice(*self.segments[seg]), **fetch_kwargs) for seg in segments]
         elif isinstance(segments, str):
-            return self._prepare_seg(slice(*self._segments[segments]), **fetch_kwargs)
+            return self._prepare_seg(slice(*self.segments[segments]), **fetch_kwargs)
         elif isinstance(segments, slice):
             return self._prepare_seg(segments, **fetch_kwargs)
         else:
@@ -409,7 +439,7 @@ class TSDatasetH(DatasetH):
 
     def setup_data(self, *args, **kwargs):
         super().setup_data(*args, **kwargs)
-        cal = self._handler.fetch(col_set=self._handler.CS_RAW).index.get_level_values("datetime").unique()
+        cal = self.handler.fetch(col_set=self.handler.CS_RAW).index.get_level_values("datetime").unique()
         cal = sorted(cal)
         # Get the datatime index for building timestamp
         self.cal = cal

qlib/data/dataset/handler.py

@@ -57,6 +57,7 @@ class DataHandler(Serializable):
         instruments=None,
         start_time=None,
         end_time=None,
+        freq="day",
         data_loader: Tuple[dict, str, DataLoader] = None,
         init_data=True,
         fetch_orig=True,
@@ -70,6 +71,8 @@ class DataHandler(Serializable):
             start_time of the original data.
         end_time :
             end_time of the original data.
+        freq :
+            frequency of data
         data_loader : Tuple[dict, str, DataLoader]
             data loader to load the data.
         init_data :
@@ -92,6 +95,7 @@ class DataHandler(Serializable):
         self.instruments = instruments
         self.start_time = start_time
         self.end_time = end_time
+        self.freq = freq
         self.fetch_orig = fetch_orig
         if init_data:
             with TimeInspector.logt("Init data"):
@@ -119,7 +123,7 @@ class DataHandler(Serializable):
         # Setup data.
         # _data may be with multiple column index level. The outer level indicates the feature set name
         with TimeInspector.logt("Loading data"):
-            self._data = self.data_loader.load(self.instruments, self.start_time, self.end_time)
+            self._data = self.data_loader.load(self.instruments, self.start_time, self.end_time, self.freq)
         # TODO: cache
 
     CS_ALL = "__all"  # return all columns with single-level index column
@@ -258,10 +262,12 @@ class DataHandlerLP(DataHandler):
         instruments=None,
         start_time=None,
         end_time=None,
+        freq="day",
         data_loader: Tuple[dict, str, DataLoader] = None,
         infer_processors=[],
         learn_processors=[],
         process_type=PTYPE_A,
+        drop_raw=False,
         **kwargs,
     ):
         """
@@ -303,6 +309,8 @@ class DataHandlerLP(DataHandler):
             - self._learn will be processed by infer_processors + learn_processors
 
               - (e.g. self._infer processed by learn_processors )
+        drop_raw: bool
+            Whether to drop the raw data
         """
 
         # Setup preprocessor
@@ -319,7 +327,8 @@ class DataHandlerLP(DataHandler):
                 )
 
         self.process_type = process_type
-        super().__init__(instruments, start_time, end_time, data_loader, **kwargs)
+        self.drop_raw = drop_raw
+        super().__init__(instruments, start_time, end_time, freq, data_loader, **kwargs)
 
     def get_all_processors(self):
         return self.infer_processors + self.learn_processors
@@ -348,7 +357,7 @@ class DataHandlerLP(DataHandler):
         """
         # data for inference
         _infer_df = self._data
-        if len(self.infer_processors) > 0:  # avoid modifying the original  data
+        if len(self.infer_processors) > 0 and not self.drop_raw:  # avoid modifying the original  data
             _infer_df = _infer_df.copy()
 
         for proc in self.infer_processors:
@@ -378,6 +387,8 @@ class DataHandlerLP(DataHandler):
                 _learn_df = proc(_learn_df)
         self._learn = _learn_df
 
+        if self.drop_raw:
+            del self._data
     # init type
     IT_FIT_SEQ = "fit_seq"  # the input of `fit` will be the output of the previous processor
     IT_FIT_IND = "fit_ind"  # the input of `fit` will be the original df
@@ -416,7 +427,11 @@ class DataHandlerLP(DataHandler):
         # TODO: Be able to cache handler data. Save the memory for data processing
 
     def _get_df_by_key(self, data_key: str = DK_I) -> pd.DataFrame:
-        df = getattr(self, {self.DK_R: "_data", self.DK_I: "_infer", self.DK_L: "_learn"}[data_key])
+        try:
+            df = getattr(self, {self.DK_R: "_data", self.DK_I: "_infer", self.DK_L: "_learn"}[data_key])
+        except AttributeError:
+            print("please set drop_raw = False if you want to use raw data")
+            raise        
         return df
 
     def fetch(

qlib/data/dataset/loader.py

@@ -19,7 +19,7 @@ class DataLoader(abc.ABC):
     """
 
     @abc.abstractmethod
-    def load(self, instruments, start_time=None, end_time=None) -> pd.DataFrame:
+    def load(self, instruments, start_time=None, end_time=None, freq="day") -> pd.DataFrame:
         """
         load the data as pd.DataFrame.
 
@@ -94,7 +94,7 @@ class DLWParser(DataLoader):
         return exprs, names
 
     @abc.abstractmethod
-    def load_group_df(self, instruments, exprs: list, names: list, start_time=None, end_time=None) -> pd.DataFrame:
+    def load_group_df(self, instruments, exprs: list, names: list, start_time=None, end_time=None, freq="day") -> pd.DataFrame:
         """
         load the dataframe for specific group
 
@@ -114,25 +114,25 @@ class DLWParser(DataLoader):
         """
         pass
 
-    def load(self, instruments=None, start_time=None, end_time=None) -> pd.DataFrame:
+    def load(self, instruments=None, start_time=None, end_time=None, freq="day") -> pd.DataFrame:
         if self.is_group:
             df = pd.concat(
                 {
-                    grp: self.load_group_df(instruments, exprs, names, start_time, end_time)
+                    grp: self.load_group_df(instruments, exprs, names, start_time, end_time, freq)
                     for grp, (exprs, names) in self.fields.items()
                 },
                 axis=1,
             )
         else:
             exprs, names = self.fields
-            df = self.load_group_df(instruments, exprs, names, start_time, end_time)
+            df = self.load_group_df(instruments, exprs, names, start_time, end_time, freq)
         return df
 
 
 class QlibDataLoader(DLWParser):
     """Same as QlibDataLoader. The fields can be define by config"""
 
-    def __init__(self, config: Tuple[list, tuple, dict], filter_pipe=None):
+    def __init__(self, config: Tuple[list, tuple, dict], filter_pipe=None, swap_level=True):
         """
         Parameters
         ----------
@@ -140,11 +140,15 @@ class QlibDataLoader(DLWParser):
             Please refer to the doc of DLWParser
         filter_pipe :
             Filter pipe for the instruments
+        swap_level :
+            Whether to swap level of MultiIndex
         """
         self.filter_pipe = filter_pipe
+        self.swap_level = swap_level
+        print("swap level", swap_level)
         super().__init__(config)
 
-    def load_group_df(self, instruments, exprs: list, names: list, start_time=None, end_time=None) -> pd.DataFrame:
+    def load_group_df(self, instruments, exprs: list, names: list, start_time=None, end_time=None, freq="day") -> pd.DataFrame:
         if instruments is None:
             warnings.warn("`instruments` is not set, will load all stocks")
             instruments = "all"
@@ -153,9 +157,10 @@ class QlibDataLoader(DLWParser):
         elif self.filter_pipe is not None:
             warnings.warn("`filter_pipe` is not None, but it will not be used with `instruments` as list")
 
-        df = D.features(instruments, exprs, start_time, end_time)
+        df = D.features(instruments, exprs, start_time, end_time, freq)
         df.columns = names
-        df = df.swaplevel().sort_index()  # NOTE: always return <datetime, instrument>
+        if self.swap_level:
+            df = df.swaplevel().sort_index()  # NOTE: if swaplevel, return <datetime, instrument>
         return df
 
 
@@ -177,7 +182,7 @@ class StaticDataLoader(DataLoader):
         self.join = join
         self._data = None
 
-    def load(self, instruments=None, start_time=None, end_time=None) -> pd.DataFrame:
+    def load(self, instruments=None, start_time=None, end_time=None, freq="day") -> pd.DataFrame:
         self._maybe_load_raw_data()
         if instruments is None:
             df = self._data