editdistance¶

Enum class¶

class symspellpy.editdistance.DistanceAlgorithm(*values)[source]¶

Supported edit distance algorithms.

LEVENSHTEIN = 0¶: Levenshtein algorithm.

DAMERAU_OSA = 1¶: Damerau optimal string alignment algorithm

LEVENSHTEIN_FAST = 2¶: Fast Levenshtein algorithm.

DAMERAU_OSA_FAST = 3¶: Fast Damerau optimal string alignment algorithm

USER_PROVIDED = 4¶: User provided custom edit distance algorithm

EditDistance class¶

class symspellpy.editdistance.EditDistance(algorithm, comparer=None)[source]¶

Edit distance algorithms.

Parameters:: algorithm (DistanceAlgorithm) – The distance algorithm to use.

_algorithm¶

The edit distance algorithm to use.

Type:: DistanceAlgorithm

_distance_comparer¶

An object to compute the relative distance between two strings. The concrete object will be chosen based on the value of _algorithm.

Type:: AbstractDistanceComparer

Raises:: ValueError – If algorithm specifies an invalid distance algorithm.

compare(string_1, string_2, max_distance)[source]¶

Compares a string to the base string to determine the edit distance, using the previously selected algorithm.

Parameters:

string_1 (str) – Base string.
string_2 (str) – The string to compare.
max_distance (int) – The maximum distance allowed.

Return type:

int

Returns:

The edit distance (or -1 if max_distance exceeded).

Distance comparer classes¶

class symspellpy.editdistance.DamerauOsa[source]¶

Provides optimized methods for computing Damerau-Levenshtein Optimal String Alignment (OSA) comparisons between two strings.

_base_char_1_costs¶

Type:: list[int]

_base_prev_char_1_costs¶

Type:: list[int]

distance(string_1, string_2, max_distance)[source]¶

Computes the Damerau-Levenshtein optimal string alignment edit distance between two strings.

Parameters:

string_1 (Optional[str]) – One of the strings to compare.
string_2 (Optional[str]) – The other string to compare.
max_distance (int) – The maximum distance that is of interest.

Return type:

int

Returns:

-1 if the distance is greater than the max_distance, 0 if the strings: are equivalent, otherwise a positive number whose magnitude increases as difference between the strings increases.

class symspellpy.editdistance.Levenshtein[source]¶

Provides Levenshtein algorithm for computing edit distance metric between two strings.

_base_char_1_costs¶

Type:: list[int]

distance(string_1, string_2, max_distance)[source]¶

Computes the Levenshtein edit distance between two strings.

Parameters:

string_1 (Optional[str]) – One of the strings to compare.
string_2 (Optional[str]) – The other string to compare.
max_distance (int) – The maximum distance that is of interest.

Return type:

int

Returns:

-1 if the distance is greater than the max_distance, 0 if the strings: are equivalent, otherwise a positive number whose magnitude increases as difference between the strings increases.

class symspellpy.editdistance.DamerauOsaFast[source]¶

Provides an interface for computing edit distance metric between two strings using the fast Damerau-Levenshtein Optimal String Alignment (OSA) algorithm.

distance(string_1, string_2, max_distance)[source]¶

Computes the Damerau-Levenshtein optimal string alignment edit distance between two strings.

Parameters:

string_1 (Optional[str]) – One of the strings to compare.
string_2 (Optional[str]) – The other string to compare.
max_distance (int) – The maximum distance that is of interest.

Return type:

int

Returns:

-1 if the distance is greater than the max_distance, 0 if the strings: are equivalent, otherwise a positive number whose magnitude increases as difference between the strings increases.

class symspellpy.editdistance.LevenshteinFast[source]¶

Provides an interface for computing edit distance metric between two strings using the fast Levenshtein algorithm.

distance(string_1, string_2, max_distance)[source]¶

Computes the Levenshtein edit distance between two strings.

Parameters:

string_1 (Optional[str]) – One of the strings to compare.
string_2 (Optional[str]) – The other string to compare.
max_distance (int) – The maximum distance that is of interest.

Return type:

int

Returns:

-1 if the distance is greater than the max_distance, 0 if the strings: are equivalent, otherwise a positive number whose magnitude increases as difference between the strings increases.