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Natural Language Processing with Python NLTK part 7 - Lemmatizing

Natural Language Processing - Lemmatizing   Stemming and Lemmatizing process goes in hand in hand. Both of these process do the same thing but in different way. In stemming we considered to cut off the last part of the word and get a meaningful word but in lemmatizing it is more considered upon getting a more meaningful word by removing infectious part and returning the vocabulary word. Lets understand with a simple example. from nltk.stem import PorterStemmer, WordNetLemmatizer # lemmatizing verbs words_verbs = [ "run" , "ran" , "running" , "gave" , "took" , "shot" ] print ( "*************Stemming verbs********************" ) for w in words_verbs: # Stemming the words print (PorterStemmer() . stem(w)) print ( "*************Lemmatizing verbs********************" ) for w in words_verbs: # lemmatize the words print (WordNetLemmatizer() . lemmatize...
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Natural Language Processing with Python NLTK part 6 - Named Entity Recognition

Natural Language Processing - NER Named entities are specific reference to something. As a part of recognizing text NLTK has allowed us to used the named entity recognition and recognize certain types of entities. Those types are as follows NE Type Examples ORGANIZATION Georgia-Pacific Corp. ,  WHO PERSON Eddy Bonte ,  President Obama LOCATION Murray River ,  Mount Everest DATE June ,  2008-06-29 TIME two fifty a m ,  1:30 p.m. MONEY 175 million Canadian Dollars ,  GBP 10.40 PERCENT twenty pct ,  18.75 % FACILITY Washington Monument ,  Stonehenge GPE South East Asia ,  Midlothian Source:  http://www.nltk.org/book/ch07.html Simple example on NER: import nltk from nltk.tokenize import word_tokenize, sent_tokenize para = " America is a country. John is a name. " sent = sent_tokenize(para) for s in sent: word = word_tokenize(s) tag = nltk . pos_tag(word) n...

Natural Language Processing with Python NLTK part 5 - Chunking and Chinking

Natural Language Processing Using regular expression modifiers we can chunk out the PoS tagged words from the earlier example. The chunking is done with regular expressions defining a chunk rule. The Chinking defines what we need to exclude from the selection. Here are list of modifiers for Python: {1,3} = for digits, u expect 1-3 counts of digits, or "places" + = match 1 or more ? = match 0 or 1 repetitions. * = match 0 or MORE repetitions $ = matches at the end of string ^ = matches start of a string | = matches either/or. Example x|y = will match either x or y [] = range, or "variance" {x} = expect to see this amount of the preceding code. {x,y} = expect to see this x-y amounts of the preceding code source: https://pythonprogramming.net/regular-expressions-regex-tutorial-python-3/ Chunking import nltk from nltk.tokenize import word_tokenize # POS tagging sent = "This will be chunked. This is for Test. World is awesome. Hello world....

Natural Language Processing with Python NLTK part 4 - PoS tagging

Natural Language Processing  PoS tagging or Part of Speech tagging is a commonly used mechanism. This will allow NLTK to tag the words that is in your corpus and give the tags accordingly. There are many tags predefined by the NLTK and here are the list. Number Tag Description 1. CC Coordinating conjunction 2. CD Cardinal number 3. DT Determiner 4. EX Existential  there 5. FW Foreign word 6. IN Preposition or subordinating conjunction 7. JJ Adjective 8. JJR Adjective, comparative 9. JJS Adjective, superlative 10. LS List item marker 11. MD Modal 12. NN Noun, singular or mass 13. NNS Noun, plural 14. NNP Proper noun, singular 15. NNPS Proper noun, plural 16. PDT Predeterminer 17. POS Possessive ending 18. PRP Personal pronoun 19. PRP$ Possessive pronoun 20. RB Adverb 21. RBR Adverb, comparative 22. RBS ...

Natural Language Processing with Python NLTK part 3 - Stemming

Natural Language Processing So this one will be about stemming. Stemming is used in NLP for various reasons Stemming is removing certain parts of the word to get the meaning of it. For example, Running when stemmed returns run, and cooking when stemmed returns cook. from nltk.stem import PorterStemmer from nltk.tokenize import word_tokenize # testing with a sentence sent = "when we run we get healthy, Running is awesome. I have ran for may miles." myWords = word_tokenize(sent) for w in myWords: print (PorterStemmer() . stem(w)) print ( "**********Custom List************" ) # Testing with several custom words listwords = [ "come" , "came" , "coming" , "run" , "running" , "added" , "adding" ] for w in listwords: print (PorterStemmer() . stem(w)) The output will be as follows:

Natural Language Processing with Python NLTK part 2 - Stop Words

Natural Language Processing Stop words are the words which we ignore due to the fact that they do not generate any specific meaning to the sentence. Words like the, is, at etc. can be removed to extract the meaning of the sentence more easily. So NLTK has introduced us a stop words filter we can easily use. Let's see how it works. from nltk.corpus import stopwords from nltk.tokenize import word_tokenize sent = "As you can see this is the blog of myself which is written by Anjula" w = word_tokenize(sent) # set English stop words stop_words = set(stopwords . words( 'english' )) # list of standard stop words in English print (stop_words) # making empty arrays to store stop words and others stop_words_in_sent = [] non_stop_words = [] # Loop through to get the stop words for x in w: if x not in stop_words: non_stop_words . append(x) else : stop_words_in_sent . append(x) # print result ...

Natural Language Processing with Python NLTK part 1 - Tokenizer

Natural Language Processing Starting with the NLP articles first we will try the  tokenizer  in the NLTK package. Tokenizer breaks a paragraph into the relevant sub strings or sentences based on the tokenizer you used. In this I will use the Sent tokenizer, word_tokenizer and TweetTokenizer which has its specific work to do. import nltk from nltk.tokenize import sent_tokenize, word_tokenize, TweetTokenizer para = "Hello there this is the blog about NLP. In this blog I have made some posts. " \ "I can come up with new content." tweet = "#Fun night. :) Feeling crazy #TGIF" # tokenizing the paragraph into sentences and words sent = sent_tokenize(para) word = word_tokenize(para) # printing the output print ( "this paragraph has " + str(len(sent)) + " sentences and " + str(len(word)) + " words" ) # print each sentence k = 1 for i in sent: print ( "sentence ...