# SmartfilterClassifier **`class SmartfilterClassifier(config)`** Bases: [`Classifier`](squirro.lib.nlp.steps.classifiers.Classifier.md#squirro.lib.nlp.steps.classifiers.Classifier) The smartfilter [`Classifier`](squirro.lib.nlp.steps.classifiers.Classifier.md#squirro.lib.nlp.steps.classifiers.Classifier) uses the Elastic Search based highlight tags and to classify text fragments. **Note** - The [`squirro.lib.nlp.steps.loaders.SquirroQueryLoader`](squirro.lib.nlp.steps.loaders.SquirroQueryLoader.md#squirro.lib.nlp.steps.loaders.SquirroQueryLoader) step needs to be run before this step, further make sure that search highlighting is switched on. It works with normal search queries and smartfilters. **Input** - all input fields need to be of type [`str`](https://docs.python.org/3.11/library/stdtypes.html#str). **Output** - the output field is filled with data of type [`str`](https://docs.python.org/3.11/library/stdtypes.html#str). It contains the extract which is encapsulated by the highlight tags. the lable_field is filled with the smartfilter_label. Parameters - `type` ([`str`](https://docs.python.org/3.11/library/stdtypes.html#str)) – smartfilter - `words_threshold` ([`int`](https://docs.python.org/3.11/library/functions.html#int)`, ``1`) – Minimum number of highlighted words to be included as an extract. - `smartfilter_label` ([`str`](https://docs.python.org/3.11/library/stdtypes.html#str)) – Label added to document if it contains an extract. **Example** ```json { "step": "classifier", "type": "smartfilter", "input_field": "body", "output_field": "extract", "smartfilter_label": "classA", "label_field": "label" } ``` Methods SummaryMethods Documentation **`process_doc(doc)`** Process a document Parameters `doc` ([`Document`](../technical/libnlp/base.md#squirro.lib.nlp.document.Document)) – Document Returns Processed document Return type [Document](../technical/libnlp/base.md#squirro.lib.nlp.document.Document)