updated some decision tree code

machineLearning/rf/decisionTree.py

@@ -10,6 +10,7 @@ from inspect import signature
 from ..utility.progressbar import Progressbar
 from collections import deque
 from concurrent.futures import ThreadPoolExecutor
+import warnings
 
 
 def saveObjectParameters(obj, saveDict, key):
@@ -225,8 +226,8 @@ class DecisionTree():
         """
         training the tree
         """
-        if not self._impurityMeasure or not self._leafFunction or not self._findSplit:
-            raise AttributeError('some (impurity, leaf func, split algo) have not been set')
+        if not self._impurityMeasure or not self._findSplit:
+            raise AttributeError('some (impurity or split algo) have not been set')
 
         # set the root node of the tree
         id = str(self.id+1).zfill(len(str(self.treeID+1)))
@@ -245,7 +246,11 @@ class DecisionTree():
         make predictions from the trained tree
         """
         if self._trained is False:
-            raise 'must train the tree before it can make predictions'
+            raise Exception('The tree must be trained before it can make predictions.')
+
+        if not self._leafFunction:
+            warnings.warn("Since no leaf function was defined, the raw leaf values are returned.")
+            return self.raw(data)
 
         # getting the raw leaf values
         rawPredictions = self.raw(data)