nltk.collocations.TrigramCollocationFinder

class nltk.collocations.TrigramCollocationFinder

Bases: AbstractCollocationFinder

A tool for the finding and ranking of trigram collocations or other association measures. It is often useful to use from_words() rather than constructing an instance directly.

default_ws = 3

__init__(word_fd, bigram_fd, wildcard_fd, trigram_fd)

Construct a TrigramCollocationFinder, given FreqDists for appearances of words, bigrams, two words with any word between them, and trigrams.

classmethod from_words(words, window_size=3)

Construct a TrigramCollocationFinder for all trigrams in the given sequence.

bigram_finder()

Constructs a bigram collocation finder with the bigram and unigram data from this finder. Note that this does not include any filtering applied to this finder.

score_ngram(score_fn, w1, w2, w3)

Returns the score for a given trigram using the given scoring function.

above_score(score_fn, min_score)

Returns a sequence of ngrams, ordered by decreasing score, whose scores each exceed the given minimum score.

apply_freq_filter(min_freq)

Removes candidate ngrams which have frequency less than min_freq.

apply_ngram_filter(fn)

Removes candidate ngrams (w1, w2, …) where fn(w1, w2, …) evaluates to True.

apply_word_filter(fn)

Removes candidate ngrams (w1, w2, …) where any of (fn(w1), fn(w2), …) evaluates to True.

classmethod from_documents(documents)

Constructs a collocation finder given a collection of documents, each of which is a list (or iterable) of tokens.

nbest(score_fn, n)

Returns the top n ngrams when scored by the given function.

score_ngrams(score_fn)

Returns a sequence of (ngram, score) pairs ordered from highest to lowest score, as determined by the scoring function provided.