Source code for nlp_primitives.stopword_count

# -*- coding: utf-8 -*-
import nltk
import numpy as np
import pandas as pd
from featuretools.primitives.base import TransformPrimitive
from woodwork.column_schema import ColumnSchema
from woodwork.logical_types import IntegerNullable, NaturalLanguage

[docs]class StopwordCount(TransformPrimitive): """Determines number of stopwords in a string. Description: Given list of strings, determine the number of stopwords characters in each string. Looks for any of the English stopwords defined in `nltk.corpus.stopwords`. Case insensitive. If a string is missing, return `NaN`. Examples: >>> x = ['This is a test string.', 'This is second string', 'third string'] >>> stopword_count = StopwordCount() >>> stopword_count(x).tolist() [3, 2, 0] """ name = "stopword_count" input_types = [ColumnSchema(logical_type=NaturalLanguage)] return_type = ColumnSchema(logical_type=IntegerNullable, semantic_tags={"numeric"}) default_value = 0 def get_function(self): def stopword_count(array): li = [] swords = set(nltk.corpus.stopwords.words("english")) tokenizer = nltk.tokenize.word_tokenize for el in array: if pd.isnull(el): li.append(np.nan) else: words = tokenizer(el) count = len([word for word in words if word.lower() in swords]) li.append(count) return pd.Series(li) return stopword_count