symspellpy

symspellpy is a Python port of SymSpell v6.3, which provides much higher speed and lower memory consumption. Unit tests from the original project are implemented to ensure the accuracy of the port.

Please note that the port has not been optimized for speed.

Usage

Installing the symspellpy module

pip install -U symspellpy

Copying the frequency dictionary to your project

Copy frequency_dictionary_en_82_765.txt (found in the inner symspellpy directory) to your project directory so you end up with the following layout:

project_dir
  +-frequency_dictionary_en_82_765.txt
  \-project.py

Sample usage (lookup and lookup_compound)

Using project.py (code is more verbose than required to allow explanation of method arguments)

import os

from symspellpy.symspellpy import SymSpell, Verbosity  # import the module

def main():
    # create object
    initial_capacity = 83000
    # maximum edit distance per dictionary precalculation
    max_edit_distance_dictionary = 2
    prefix_length = 7
    sym_spell = SymSpell(initial_capacity, max_edit_distance_dictionary,
                         prefix_length)
    # load dictionary
    dictionary_path = os.path.join(os.path.dirname(__file__),
                                   "frequency_dictionary_en_82_765.txt")
    term_index = 0  # column of the term in the dictionary text file
    count_index = 1  # column of the term frequency in the dictionary text file
    if not sym_spell.load_dictionary(dictionary_path, term_index, count_index):
        print("Dictionary file not found")
        return

    # lookup suggestions for single-word input strings
    input_term = "memebers"  # misspelling of "members"
    # max edit distance per lookup
    # (max_edit_distance_lookup <= max_edit_distance_dictionary)
    max_edit_distance_lookup = 2
    suggestion_verbosity = Verbosity.CLOSEST  # TOP, CLOSEST, ALL
    suggestions = sym_spell.lookup(input_term, suggestion_verbosity,
                                   max_edit_distance_lookup)
    # display suggestion term, term frequency, and edit distance
    for suggestion in suggestions:
        print("{}, {}, {}".format(suggestion.term, suggestion.count,
                                  suggestion.distance))

    # lookup suggestions for multi-word input strings (supports compound
    # splitting & merging)
    input_term = ("whereis th elove hehad dated forImuch of thepast who "
                  "couqdn'tread in sixtgrade and ins pired him")
    # max edit distance per lookup (per single word, not per whole input string)
    max_edit_distance_lookup = 2
    suggestions = sym_spell.lookup_compound(input_term,
                                            max_edit_distance_lookup)
    # display suggestion term, edit distance, and term frequency
    for suggestion in suggestions:
        print("{}, {}, {}".format(suggestion.term, suggestion.count,
                                  suggestion.distance))

if __name__ == "__main__":
    main()

Expected output:

members, 226656153, 1

where is the love he had dated for much of the past who couldn't read in six grade and inspired him, 300000, 10

Sample usage (word_segmentation)

Using project.py (code is more verbose than required to allow explanation of method arguments)

import os

from symspellpy.symspellpy import SymSpell, Verbosity  # import the module

def main():
      edit_distance_max = 0
      prefix_length = 7
      sym_spell = SymSpell(83000, edit_distance_max, prefix_length)
      sym_spell.load_dictionary(dictionary_path, 0, 1)

      typo = "thequickbrownfoxjumpsoverthelazydog"
      correction = "the quick brown fox jumps over the lazy dog"
      result = sym_spell.word_segmentation(typo)
    # create object
    initial_capacity = 83000
    # maximum edit distance per dictionary precalculation
    max_edit_distance_dictionary = 0
    prefix_length = 7
    sym_spell = SymSpell(initial_capacity, max_edit_distance_dictionary,
                         prefix_length)
    # load dictionary
    dictionary_path = os.path.join(os.path.dirname(__file__),
                                   "frequency_dictionary_en_82_765.txt")
    term_index = 0  # column of the term in the dictionary text file
    count_index = 1  # column of the term frequency in the dictionary text file
    if not sym_spell.load_dictionary(dictionary_path, term_index, count_index):
        print("Dictionary file not found")
        return

    # a sentence without any spaces
    input_term = "thequickbrownfoxjumpsoverthelazydog"
    
    result = sym_spell.word_segmentation(input_term)
    # display suggestion term, term frequency, and edit distance
    print("{}, {}, {}".format(result.corrected_string, result.distance_sum,
                              result.log_prob_sum))

if __name__ == "__main__":
    main()

Expected output:

the quick brown fox jumps over the lazy dog 8 -34.491167981910635