panphon 0.5

Tools for using the International Phonetic Alphabet with phonological features

This package constitutes a database of segments in the International Phonetic Alphabet (IPA) and their equivalents in terms of (articulatory) phonological features. They include both data files and the tool generate_ipa_all.py, which allows the application of rules for diacritics and modifiers to collections of IPA characters, data files, and configuration/rule files and well as the tool validate_ipa.py, which checks Unicode IPA text from STDIN for well-formedness.

Python API for Accessing Phonological Features of IPA Segments

The panphon module provides a straightforward API that allows users and developers to access the segment-feature relationships encoded in the IPA database panphon/data/ipa_all.csv.

>>> import panphon.panphon as panphon
>>> ft = panphon.FeatureTable()
>>> ft.ftr_match(set([(u'+', u'syl')]), u'a')
True
>>> ft.segs(u'pʲãk')
[u'p\u02b2', u'a\u0303', u'k']\
>>> ft.word_fts(u'pʲãk')
[set([(u'-', u'syl'), (u'-', u'long'), (u'-', u'voi'), (u'+', u'ant'), (u'-', u'cg'), (u'+', u'hi'), (u'-', u'son'), (u'0', u'tense'), (u'-', u'lat'), (u'-', u'back'), (u'-', u'cont'), (u'-', u'nas'), (u'-', u'lo'), (u'0', u'distr'), (u'-', u'round'), (u'-', u'delrel'), (u'+', u'lab'), (u'-', u'sg'), (u'+', u'cons'), (u'0', u'strid'), (u'-', u'cor')]), set([(u'+', u'son'), (u'+', u'tense'), (u'+', u'cont'), (u'+', u'nas'), (u'+', u'lo'), (u'+', u'voi'), (u'-', u'cg'), (u'-', u'hi'), (u'-', u'lat'), (u'+', u'syl'), (u'0', u'strid'), (u'-', u'long'), (u'-', u'cor'), (u'0', u'distr'), (u'-', u'round'), (u'-', u'delrel'), (u'0', u'ant'), (u'-', u'sg'), (u'+', u'back'), (u'-', u'cons'), (u'-', u'lab')]), set([(u'-', u'syl'), (u'-', u'lab'), (u'-', u'voi'), (u'0', u'distr'), (u'+', u'back'), (u'-', u'cg'), (u'+', u'hi'), (u'-', u'son'), (u'0', u'tense'), (u'-', u'lat'), (u'-', u'cont'), (u'-', u'nas'), (u'-', u'lo'), (u'-', u'ant'), (u'-', u'round'), (u'-', u'delrel'), (u'-', u'sg'), (u'+', u'cons'), (u'0', u'strid'), (u'-', u'cor'), (u'-', u'long')])]

Summary of Functionality

Operations on feature sets and segments

The FeatureTable class includes a broad range of operations on features and segments (consonants and vowels).

Fixed-width pattern matching

The FeatureTable class also allows matching of fixed-width, feature-based patterns.

Sonority calculations

The Sonority class has methods for computing sonority scores for segments.

Feature edit distance

The Distance class includes methods for calculating edit distance, both in which the cost of substitutions is based upon Hamming distance between the feature vectors and in which the cost of substitutions are based upon edit weights for individual features.

The panphon.distance Module

This module includes the Distance class, which includes various methods for computing the distance between Unicode IPA strings, including convenience methods (really “inconvenience methods”) for computing Levenshtein distance, but–more importantly–methods for computing similarity metrics related to articulatory features. The methods include the following:

panphon.distance.Distance .levenshtein_distance

A Python implementation of Levenshtein’s string edit distance.

panphon.distance.Distance .fast_levenshtein_distance

A C implementation of Levenshtein’s string edit distance. Unsurprisingly, must faster than the former.

panphon.distance.Distance .dogol_prime_distance

Fast Levenshtein distance after collapsing segments into an enhanced version of Dogolpolsky’s equivalence classes.

panphon.distance.Distance .feature_edit_distance

Edit distance where each feature-edit has cost 1/22. Edits from unspecified to specified cost 1/44.

panphon.distance.Distance .hamming_feature_edit_distance

Edit distance where each feature-edit has cost 1/22. Edits from unspecified to specified also cost 1/22. Insertions and substitutions each cost 1.

panphon.distance.Distance .weighted_feature_edit_distance

Edit distance where costs of feature edits are differently weighted depending on their class and subjective variability. All of these methods have the same interface and patterns of usage, demonstrated below:

>>> import panphon.distance
>>> dst = panphon.distance.Distance()
>>> dst.dogol_prime_distance(u'pops', u'bobz')
0
>>> dst.dogol_prime_distance(u'pops', u'bobo')
1

Scripts

The generate_ipa_all.py Script

Summary

This small Python program allows the user to apply sets of rules, defined in YAML, for adding diacritics and modifiers to IPA segments based upon their phonological features.

Usage

To generate a segment features file (ipa_all.csv), use the following in the panphon data directory:

$ generate_ipa_all.py ipa_bases.csv -d diacritic_definitions.yml -s sort_order.yml ipa_all.csv

Note that this will overwrite your existing ipa_all.csv file, which is often what you want.

The validate_ipa.py Script

[To be added.]

The align_wordlists.py Script

[To be added.]

Data Files

This package also includes multiple data files. The most important of these is ipa_bases.csv, a CSV table of IPA characters with definitions in terms of phonological features. From it, and the diacritics_definitions.yml file, the comprehensive ipa_all.csv is generated.

IPA Character Databases: ipa_bases.csv and ipa_all.csv

The IPA Character Table is a CSV file in which the first column contains an IPA segment and each subsequent column contains a phonological feature, coded as +, -, or 0. The features are as follows:

• syl: syllabic

• son: sonorant

• cons: consonantal

• cont: continuant

• delrel: delayed release

• lat: lateral

• nas: nasal

• strid: strident

• voi: voice

• sg: spread glottis

• cg: constricted glottis

• ant: anterior

• cor: coronal

• distr: distributed

• lab: labial

• hi: high (vowel/consonant, not tone)

• lo: low (vowel/consonant, not tone)

• back: back

• round: round

• tense: tense

Inspiration for the data in these tables is drawn primarily from two sources: the data files for HsSPE and Bruce Hayes’s feature spreadsheet. It has since be re-rationalizeds based on evidence from a wide range of sources. As such, any special relationship to these prior inspirations has been eliminated.

The IPA Character Table ipa_bases.csv is intended to contain all of the unmodified segmental symbols in IPA, as well as all common affricates and dually-articulated segments. It is meant to be augmented by the rule-driven application of diacritics and modifiers.

Configuration and Rule Files

This package includes two files that control the behavior of generate_ipa_all.py. These are intended to be edited by the end user. Both are written in YAML, a standardized and human-readable and editable data serialization language.

Sort Order Specification: sort_order.yml

The file sort_order.yml controls the ordering of segments in the output of the Diacritic Application Tool. It is a sequence of maps, each with two fields:

• name The name of a feature.

• reverse A boolean value (True or False) specifying whether sorting on the named feature will be reversed or not.

The order of the features determines the priority of sorting.

The file sort_order_schema_.yml is a Kwalify schema that defines a syntactically valid sort order file.

Diacritic and Modifier Rules: diacritic_definitions.yml

The most important file for controlling the Diacritic Application Tool is diacritic_definitions.yml, a list of rules for applying diacritics and modifiers to IPA segments based on their phonological features. It has two sections, diacritics and combinations. Each of these is the key to an item in the top-level map.

Diacritics

The key diacritics points to a list of rules for applying diacritics/modifiers to bases. Each rule is a map with the following fields:

• marker. The Unicode diacritic or modifier.

• name. The name of the series derived from applying the diacritic or modifier.

• postion. The position of the diacritic relative to the base (pre or post).

• conditions. A list of conditions, each of them consisting of an associative array of feature specifications, under which the diacritic or modifier will be applied to a base.

• exclude. A sequence of segments to be excluded from the application of the diacritic/modifier even if they match the conditions.

• content. The feature specifications that will be set if the diacritic or modifier is applied, given as a map of feature specifications.

Combinations

The key combinations likewise points to a list of rules for combining the rules in diacritics. These rules are very simple, and include only the following fields:

• name. The name of the combined category.

• combines. A sequence of the names of the rules from diacritics that are to be combined.

The file diacritic_definitions_schema.yml is a Kwalify schema that defines a syntactically valid diacritics definition file.