pyuegc

A pure Python implementation of the Unicode algorithm for breaking strings of text (i.e., code point sequences) into extended grapheme clusters (“user-perceived characters”) as specified in UAX #29, “Unicode Text Segmentation.” This package conforms to version 16.0 of the Unicode standard, released in September 2024, and has been rigorously tested against the official Unicode test file to ensure accuracy.

Installation and updates

To install the package, run:

pip install pyuegc

To upgrade to the latest version, run:

pip install pyuegc --upgrade

Unicode character database (UCD) version

To retrieve the version of the Unicode character database in use:

>>> from pyuegc import UCD_VERSION
>>> UCD_VERSION
'16.0.0'

Example usage

from pyuegc import EGC

def _output(unistr, egc):
    return f"""\
# String: {unistr}
# Length of string: {len(unistr)}
# EGC: {egc}
# Length of EGC: {len(egc)}
"""

unistr = "Python"
egc = EGC(unistr)
print(_output(unistr, egc))
# String: Python
# Length of string: 6
# EGC: ['P', 'y', 't', 'h', 'o', 'n']
# Length of EGC: 6

unistr = "e\u0301le\u0300ve"
egc = EGC(unistr)
print(_output(unistr, egc))
# String: élève
# Length of string: 7
# EGC: ['é', 'l', 'è', 'v', 'e']
# Length of EGC: 5

unistr = "Z̷̳̎a̸̛ͅl̷̻̇g̵͉̉o̸̰͒"
egc = EGC(unistr)
print(_output(unistr, egc))
# String: Z̷̳̎a̸̛ͅl̷̻̇g̵͉̉o̸̰͒
# Length of string: 20
# EGC: ['Z̷̳̎', 'a̸̛ͅ', 'l̷̻̇', 'g̵͉̉', 'o̸̰͒']
# Length of EGC: 5

unistr = "기운찰만하다"
egc = EGC(unistr)
print(_output(unistr, egc))
# String: 기운찰만하다
# Length of string: 15
# EGC: ['기', '운', '찰', '만', '하', '다']
# Length of EGC: 6

unistr = "পৌষসংক্রান্তির"
egc = EGC(unistr)
print(_output(unistr, egc))
# String: পৌষসংক্রান্তির
# Length of string: 14
# EGC: ['পৌ', 'ষ', 'সং', 'ক্রা', 'ন্তি', 'র']
# Length of EGC: 6

Reversing a string directly may mess up diacritics, whereas reversing using EGC correctly preserves the visual appearance of characters regardless of the Unicode normalization form:

unistr = "ai\u0302ne\u0301e"  # aînée

print(f"# Reversed string: {''.join(reversed(unistr))!r}")
# Reversed string: 'éen̂ia'

print(f"# EGC processed and reversed: {''.join(reversed(EGC(unistr)))!r}")
# EGC processed and reversed: 'eénîa'

Related resources

This implementation is based on the following resources:

• “Grapheme Clusters,” in the Unicode core specification, version 16.0.0
• Unicode Standard Annex #29: Unicode Text Segmentation, revision 45

Licenses

The code is licensed under the MIT license.

Usage of Unicode data files is governed by the UNICODE TERMS OF USE. Further specifications of rights and restrictions pertaining to the use of the Unicode data files and software can be found in the Unicode Data Files and Software License, a copy of which is included as UNICODE-LICENSE.