Stop word dictionary Leave feedback

The StopWordDictionary class is designed to store stop words in an index. Stop words are excluded from indexing only if the use_stop_words index setting is enabled. Information on using stop words during indexing is provided on the Indexing with stop words page.

Note

Stop words define which terms of documents are indexed. Therefore, the stop word dictionary and the use_stop_words setting of an index can be changed only while the index contains no documents and is not performing an operation; otherwise, a change raises RuntimeError. A call that does not change the content of the dictionary is allowed. Configure stop words after creating a new index and before adding documents. See also the Index format and compatibility page.

The dictionary keeps words in lower case without leading and trailing white space. Therefore, the letter case of words does not matter when words are added, removed or checked.

To get the number of stop words in the dictionary, use the count property.

To add stop words to the dictionary, use the add_range method.

To remove words from the dictionary, use the remove_range method.

To check for a word in the dictionary, use the contains method. The method ignores the letter case of the word.

To remove all words from the dictionary, use the clear method.

To export words to a file, use the export_dictionary method.

To import words from a file, use the import_dictionary method. Errors of exporting and importing are reported by the error_occurred event of the index instead of exceptions.

The following example demonstrates the use of methods of the stop word dictionary.

from groupdocs.search import Index, IndexSettings

# Creating an index settings instance
settings = IndexSettings()
settings.use_stop_words = True  # Enabling the use of stop words during indexing

# Creating a new index in the specified folder; the dictionary can be changed only while the index contains no documents
index = Index("./index", settings, True)

stop_words = index.dictionaries.stop_word_dictionary

if stop_words.count > 0:
    # Removing all words from the dictionary
    stop_words.clear()

# Adding stop words to the dictionary
words = ["a", "an", "the", "but", "by"]
stop_words.add_range(words)

# The letter case of words is ignored
if stop_words.contains("But") and stop_words.contains("BY"):
    # Removing words from the dictionary
    stop_words.remove_range(["but", "by"])

# Exporting words to a file
stop_words.export_dictionary("./StopWords.txt")

# Importing words from a file
stop_words.import_dictionary("./StopWords.txt")
print("Stop words:", stop_words.count)

# Indexing documents; after that, the stop words of the index cannot be changed
index.add("./documents")

Stop words: 3

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