bratlib

Bratlib is a library for natural language processing data facilitation with the brat standoff format of text annotations. At the core of this library are classes that represent individual annotations, documents as a whole, and data sets as a whole. These classes can be used as-is or can be extended for different use cases, while providing a format that can be shared between NLP libraries as part of a larger end-to-end solution.

Bratlib also contains tools for analyzing document annotations, including calculators for binary classification scores. These are available as importable functions or as command line tools.

Usage

The primary data facilitation classes are defined in bratlib.data

• BratDataset represents a directory containing ann and txt files. The constructor BratDataset.from_directory(dir_path) with automatically read the directory and pair any matching ann and txt files into BratFile instances. BratDataset instances are iterables of BratFile instances.
• BratFile represents an individual ann file and its respective txt file, if it exists. The constructor BratFile.from_ann_path(ann_path) will handle finding the txt file. BratFile instances search the ann file they represent for all their entries that are formatted correctly.

Example

Consider example.ann

T1  A 1 2  lorem
T2  B 3 5;5 6  ipsum
R1  C Arg1:T1 Arg2:T2

>>> from bratlib import data as bd
>>> ann = bd.BratFile.from_ann_path('example.ann')
>>> list(ann.entities)
[bd.Entity(tag='A', spans=[(1, 2)], mention='lorem'), bd.Entity(tag='B', spans=[(3, 5), (5, 6)], mention='ipsum')]
>>> list(ann.relations)
[bd.Relation(relation='C', arg1=bd.Entity(tag='A', spans=[(1, 2)], mention='lorem'), arg2=bd.Entity(tag='B', spans=[(3, 5), (5, 6)], mention='ipsum'))]