add class_name attribute to freqai interface

freqtrade/freqai/freqai_interface.py

@@ -83,6 +83,7 @@ class IFreqaiModel(ABC):
         self.CONV_WIDTH = self.freqai_info.get('conv_width', 1)
         if self.ft_params.get("inlier_metric_window", 0):
             self.CONV_WIDTH = self.ft_params.get("inlier_metric_window", 0) * 2
+        self.class_names: List[str] = []  # used in classification children classes
         self.pair_it = 0
         self.pair_it_train = 0
         self.total_pairs = len(self.config.get("exchange", {}).get("pair_whitelist"))

freqtrade/freqai/prediction_models/PyTorchClassifier.py

@@ -22,8 +22,11 @@ class PyTorchClassifier(BasePyTorchModel):
     User must implement fit method
 
     Important!
-    User must declare the target class names in the strategy, under
-    IStrategy.set_freqai_targets method.
+
+    - User must declare the target class names in the strategy,
+    under IStrategy.set_freqai_targets method.
+
+    for example, in your strategy:
     ```
         def set_freqai_targets(self, dataframe: DataFrame, metadata: Dict, **kwargs):
             self.freqai.class_names = ["down", "up"]
@@ -31,7 +34,6 @@ class PyTorchClassifier(BasePyTorchModel):
                                                   dataframe["close"], 'up', 'down')
 
             return dataframe
-    ```
     """
     def __init__(self, **kwargs):
         super().__init__(**kwargs)
@@ -55,7 +57,7 @@ class PyTorchClassifier(BasePyTorchModel):
         if not class_names:
             raise ValueError(
                 "Missing class names. "
-                "self.model.model_meta_data[\"class_names\"] is None."
+                "self.model.model_meta_data['class_names'] is None."
             )
 
         if not self.class_name_to_index:
@@ -136,10 +138,11 @@ class PyTorchClassifier(BasePyTorchModel):
         self.encode_class_names(data_dictionary, dk, class_names)
 
     def get_class_names(self) -> List[str]:
-        if not hasattr(self, "class_names"):
+        if not self.class_names:
             raise ValueError(
-                "Missing attribute: self.class_names "
+                "self.class_names is empty, "
                 "set self.freqai.class_names = ['class a', 'class b', 'class c'] "
                 "inside IStrategy.set_freqai_targets method."
             )
+
         return self.class_names

freqtrade/freqai/prediction_models/PyTorchMLPClassifier.py

@@ -56,7 +56,7 @@ class PyTorchMLPClassifier(PyTorchClassifier):
         User sets up the training and test data to fit their desired model here
         :param data_dictionary: the dictionary constructed by DataHandler to hold
                                 all the training and test data/labels.
-        :raises ValueError: If self.class_names is empty.
+        :raises ValueError: If self.class_names is not defined in the parent class.
         """
 
         class_names = self.get_class_names()