Package nltk :: Module text :: Class ContextIndex

type ContextIndex

object --+
         |
        ContextIndex

A bidirectional index between words and their 'contexts' in a text. The context of a word is usually defined to be the words that occur in a fixed window around the word; but other definitions may also be used by providing a custom context function.

Instance Methods

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__init__(self, tokens, context_func=None, filter=None, key=<function <lambda> at 0x7a0070>)

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list of token

tokens(self)
Returns: The document that this context index was created from.

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word_similarity_dict(self, word)
Return a dictionary mapping from words to 'similarity scores,' indicating how often these two words occur in the same context.

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similar_words(self, word, n=20)

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common_contexts(self, words, fail_on_unknown=False)
Find contexts where the specified words can all appear; and return a frequency distribution mapping each context to the number of times that context was used.

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Static Methods

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_default_context(tokens, i)
One left token and one right token, normalized to lowercase

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Method Details

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init(self, tokens, context_func=None, filter=None, key=<function <lambda> at 0x7a0070>)
(Constructor)

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Overrides: object.__init__: (inherited documentation)

tokens(self)

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Returns: list of token: The document that this context index was created from.

common_contexts(self, words, fail_on_unknown=False)

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Find contexts where the specified words can all appear; and return a frequency distribution mapping each context to the number of times that context was used.

Parameters:

words (str) - The words used to seed the similarity search
fail_on_unknown - If true, then raise a value error if any of the given words do not occur at all in the index.

type ContextIndex

__init__(self, tokens, context_func=None, filter=None, key=<function <lambda> at 0x7a0070>) (Constructor)

tokens(self)

common_contexts(self, words, fail_on_unknown=False)

init(self, tokens, context_func=None, filter=None, key=<function <lambda> at 0x7a0070>)
(Constructor)