PyLangAcq: Language Acquisition Research in Python¶

PyLangAcq is a Python library for language acquisition research.

• Reading and writing the CHAT data format used by TalkBank and CHILDES datasets

• Intuitive Python data structures for flexible data access and manipulation

• Standard developmental measures readily available: Mean length of utterance (MLU), type-token ratio (TTR), and Index of Productive Syntax (IPSyn)

• Direct support and powerful extensions possible for CHAT-formatted conversational datasets more generally

Since v0.20.0 (February 2026), PyLangAcq depends on Rustling, a library for efficiently handling CHAT data and other computational linguistics tasks.

pip install --upgrade pylangacq

conda install -c conda-forge pylangacq

@TechReport{lee-et-al-pylangacq:2016,
   Title       = {Working with CHAT transcripts in Python},
   Author      = {Lee, Jackson L. and Burkholder, Ross and Flinn, Gallagher B. and Coppess, Emily R.},
   Institution = {Department of Computer Science, University of Chicago},
   Year        = {2016},
   Number      = {TR-2016-02},
}