flexlibs

flexlibs is a library for accessing FieldWorks Language Explorer (FLEx) [1] projects.

flexlibs handles the necessary initialisation of the FLEx engine, and provides a class (FLExProject) for opening a FLEx project and working with its contents.

For the GUI application that runs Python scripts/plugins on FLEx databases see FLExTools [2], which is built on flexlibs2.

Requirements

Python 3.8 - 3.13.

Python for .NET [3] version 3.0.3+.

FieldWorks Language Explorer 9.0.17 - 9.3.1.

32-bit vs 64-bit

The Python architecture must match that of FieldWorks. I.e. Install 32-bit Python for 32-bit Fieldworks, and 64-bit Python for 64-bit Fieldworks.

Installation

Run: pip install flexlibs

Usage

Basic usage:

import flexlibs2
flexlibs2.FLExInitialize()
p = flexlibs2.FLExProject()
p.OpenProject('parser-experiments')
p.GetPartsOfSpeech()
# ['Adverb', 'Noun', 'Pro-form', 'Pronoun', 'Verb', 'Copulative verb', 'Ditransitive verb', 'Intransitive verb', 'Transitive verb', 'Coordinating connective']

# The API documentation is an HTML file
os.startfile(flexlibs2.APIHelpFile)
...
p.CloseProject()
flexlibs2.FLExCleanup()

Version 2.0+ Operations Classes

Version 2.0 introduces comprehensive Operations classes providing CRUD (Create, Read, Update, Delete) methods for all major FLEx data types. These are organized into topic areas matching FLEx's structure:

• Grammar: Parts of Speech, Phonemes, Grammatical Categories, Morphology
• Lexicon: Entries, Senses, Examples, Pronunciations, Variants, Etymology
• Texts & Words: Texts, Wordforms, Analyses, Paragraphs, Segments
• Notebook: Notes, People, Locations, Anthropology data
• Lists: Publications, Agents, Overlays, Possibility Lists
• System: Writing Systems, Custom Fields, Project Settings

Example usage:

import flexlibs2
flexlibs2.FLExInitialize()

project = flexlibs2.FLExProject()
project.OpenProject('MyProject', writeEnabled=True)

# Create a new lexical entry
entry = project.LexEntry.Create("run", "stem")

# Add a sense with gloss
sense = project.LexEntry.AddSense(entry, "to move rapidly on foot")
project.Senses.SetGloss(sense, "run", "en")

# Set part of speech
verb = project.POS.Find("Verb")
project.Senses.SetPOS(sense, verb)

# Add an example sentence
example = project.Examples.Create(sense,
    "The dog runs in the park.", "en")

project.CloseProject()
flexlibs2.FLExCleanup()

All v1.x API methods remain available for backward compatibility.

What's New in v2.2

Version 2.2 introduces Wrapper Classes and Smart Collections that simplify working with polymorphic types in FieldWorks. These eliminate the need for manual type checking and casting.

Key Features:

• Automatic Type Casting: No more checking ClassName or casting to concrete types
• Smart Collections: Type-aware display showing diversity of data
• Convenience Filters: Easy filtering without manual type checks
• Capability-Based API: Check what's available instead of checking type
• Zero Breaking Changes: All existing code continues to work

Example - Phonological Rules (v2.2):

from flexlibs2 import FLExProject
from flexlibs2.wrappers import PhonologicalRule

project = FLExProject()
project.OpenProject('MyProject')

# Get all rules - returns smart collection with wrapped objects
rules = project.PhonologicalRuleOperations().GetAll()

# Type-aware display
print(rules)  # Shows: PhRegularRule: 7, PhMetathesisRule: 3, etc.

# Convenience filters
regular_rules = rules.regular_rules
metathesis_rules = rules.metathesis_rules

# Transparent property access across types
for rule in rules:
    if rule.has_output_specs:
        print(f"Outputs: {rule.output_segments}")
    if rule.has_metathesis_parts:
        print(f"Metathesis: {rule.left_part}, {rule.right_part}")

Currently Supported Domains:

• Grammar: Phonological Rules, Phonological Contexts
• Lexicon: Morphosyntactic Analyses (MSAs)

More domains coming in v2.3+

Migration Guide: See MIGRATION.md for detailed examples comparing old and new API.

Contract Testing

A pre-commit hook verifies that LibLCM API dependencies stay consistent as you develop. On machines with FieldWorks installed, the full suite checks every type and member flexlibs2 depends on and detects regressions across LibLCM upgrades.

Setup: python hooks/install.py

See Contract Testing Guide for details.

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[1]	https://software.sil.org/fieldworks/

[2]	https://github.com/cdfarrow/flextools/wiki/

[3]	https://github.com/pythonnet/pythonnet/wiki