NLTK is a leading platform for building Python programs to work with human language data. It provides easy-to-use interfaces to lexical resources such as WordNet.It also has text processing libraries for classification, tokenization, stemming, tagging, parsing, and semantic reasoning
Pattern has tools for natural language processing like part-of-speech taggers, n-gram search, sentiment analysis, WordNet.It supports machine learning vector space model, clustering, SVM.
TextBlob is a Python library for processing textual data. It provides a simple API for diving into common natural language processing tasks such as part-of-speech tagging, noun phrase extraction, sentiment analysis, classification, translation, and more.
Gensim is a Python library for topic modelling, document indexing and similarity retrieval with large corpora. It can process input larger than RAM. According to the author it is "the most robust, efficient and hassle-free piece of software to realize unsupervised semantic modelling from plain text"
Python Natural Language Processing Library(pronounced as: pineapple) is a Python library for Natural Language Processing. It is a collection of various independent or loosely interdependent modules useful for common, and less common, NLP tasks. PyNLPl can be used for example the computation of n-grams, frequency lists and distributions, language models. There are also more complex data types, such as Priority Queues, and search algorithms, such as Beam Search.
It’s commercial open source software. Industrial strength NLP with Python and Cython.Its a pipeline for fast, state-of-the-art natural language processing.
Polyglot is a natural language pipeline that supports massive multilingual applications. It supports tokenization for 165 languages, Language detection for 196 languages, Named Entity Recognition for 40 languages, Part of Speech Tagging for 16 languages, Sentiment Analysis for 136 languages, Word Embeddings for 137 languages, Morphological analysis for 135 languages, Transliteration for 69 languages
MontyLingua is a free, commonsense-enriched, end-to-end natural language
understander for English. Feed raw English text into MontyLingua, and the output
will be a semantic interpretation of that text. Perfect for information
retrieval and extraction, request processing, and question answering. From
English sentences, it extracts subject/verb/object tuples, extracts adjectives,
noun phrases and verb phrases, and extracts people's names, places, events,
dates and times, and other semantic information
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