GH-38: Improve label class.

flair/data.py

@@ -93,6 +93,10 @@ def load(cls, name: str):
 
 
 class Label:
+    """
+    This class represents a label of a sentence. Each label has a name and optional a confidence value. The confidence
+    value needs to be between 0.0 and 1.0. Default value for the confidence is 0.0.
+    """
     def __init__(self, name: str, confidence: float = 0.0):
         self.name = name
         self.confidence = confidence
@@ -103,16 +107,21 @@ def name(self):
 
     @name.setter
     def name(self, name):
-        self._name = name
+        if not name:
+            raise ValueError('Incorrect label name provided. Label name needs to be set.')
+        else:
+            self._name = name
 
     @property
     def confidence(self):
-        return self._name
+        return self._confidence
 
     @confidence.setter
     def confidence(self, confidence):
         if 0.0 <= confidence <= 1.0:
             self._confidence = confidence
+        else:
+            self._confidence = 0.0
 
 
 class Token:

tests/test_data.py

@@ -179,6 +179,20 @@ def test_tagged_corpus_make_vocab_dictionary():
     assert('.' in vocab.get_items())
 
 
+def test_label_set_confidence():
+    label = Label('class_1', 3.2)
+
+    assert (0.0 == label.confidence)
+    assert ('class_1' == label.name)
+
+    label.confidence = 0.2
+
+    assert (0.2 == label.confidence)
+
+    with pytest.raises(ValueError):
+        label.name = ''
+
+
 def test_tagged_corpus_make_label_dictionary():
     sentence_1 = Sentence('sentence 1', labels=[Label('class_1')])
     sentence_2 = Sentence('sentence 2', labels=[Label('class_2')])