Created Indico base class, and abstracted text extractor logic

pliers/extractors/__init__.py

@@ -1,7 +1,7 @@
 ''' Extractor hierarchy. '''
 
 from .base import ExtractorResult, merge_results
-from .api import IndicoAPIExtractor, ClarifaiAPIExtractor
+from .api import IndicoAPITextExtractor, ClarifaiAPIExtractor
 from .audio import STFTAudioExtractor, MeanAmplitudeExtractor
 from .google import (GoogleVisionAPIFaceExtractor,
                      GoogleVisionAPILabelExtractor,

pliers/extractors/api.py

@@ -23,7 +23,8 @@
 
 class IndicoAPIExtractor(Extractor):
 
-    ''' Uses the Indico API to extract sentiment of text.
+    ''' Base class for all Indico API Extractors
+
     Args:
         api_key (str): A valid API key for the Indico API. Only needs to be
             passed the first time the extractor is initialized.
@@ -61,6 +62,22 @@ def __init__(self, api_key=None, models=None):
                        "personality, personas, text_features.")
                 raise ValueError(msg)
 
+class IndicoAPITextExtractor(IndicoAPIExtractor):
+
+    ''' Base class for all Indico API Extractors that work on text, such as
+    sentiment extraction.
+
+    Args:
+        api_key (str): A valid API key for the Indico API. Only needs to be
+            passed the first time the extractor is initialized.
+        models (list): The names of the Indico models to use.
+    '''
+
+    _optional_input_type = (TextStim, ComplexTextStim)
+
+    def __init__(self, api_key=None, models=None):
+        super(IndicoAPITextExtractor, self).__init__()
+
     def _extract(self, stim):
 
         if isinstance(stim, TextStim):