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import numpy as np
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import nltk
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from nltk.stem.porter import PorterStemmer
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stemmer = PorterStemmer()
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def tokenize(sentence):
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"""
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split sentence into array of words/tokens
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a token can be a word or punctuation character, or number
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"""
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return nltk.word_tokenize(sentence)
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def stem(word):
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"""
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stemming = find the root form of the word
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examples:
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words = ["organize", "organizes", "organizing"]
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words = [stem(w) for w in words]
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-> ["organ", "organ", "organ"]
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"""
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return stemmer.stem(word.lower())
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def bag_of_words(tokenized_sentence, words):
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"""
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return bag of words array:
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1 for each known word that exists in the sentence, 0 otherwise
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example:
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sentence = ["hello", "how", "are", "you"]
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words = ["hi", "hello", "I", "you", "bye", "thank", "cool"]
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bog = [ 0 , 1 , 0 , 1 , 0 , 0 , 0]
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"""
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sentence_words = [stem(word) for word in tokenized_sentence]
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bag = np.zeros(len(words), dtype=np.float32)
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for idx, w in enumerate(words):
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if w in sentence_words:
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bag[idx] = 1
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return bag |