Skip to content

[3.14] gh-74902: Add Unicode Grapheme Cluster Break algorithm (GH-143076) #148247

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Draft
StanFromIreland wants to merge 3 commits into
base: 3.14
Choose a base branch
from
Draft

[3.14] gh-74902: Add Unicode Grapheme Cluster Break algorithm (GH-143076) #148247

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
f413b87
[3.14] gh-74902: Add Unicode Grapheme Cluster Break algorithm (GH-143…
serhiy-storchaka Jan 14, 2026
a4665b5
Fix refleaks in new unicodedata classes added in gh-74902 (GH-143843)
serhiy-storchaka Jan 14, 2026
9efe825
gh-74902: Avoid hitting unicode.org for test data (GH-144195)
zware Jan 23, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
294 changes: 278 additions & 16 deletions Lib/test/test_unicodedata.py
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -30,6 +30,26 @@ def iterallchars():
maxunicode = 0xffff if quicktest else sys.maxunicode
return map(chr, range(maxunicode + 1))


def check_version(testfile):
hdr = testfile.readline()
return unicodedata.unidata_version in hdr


def download_test_data_file(filename):
TESTDATAURL = f"http://www.pythontest.net/unicode/{unicodedata.unidata_version}/{filename}"

try:
return open_urlresource(TESTDATAURL, encoding="utf-8", check=check_version)
except PermissionError:
raise unittest.SkipTest(
f"Permission error when downloading {TESTDATAURL} "
f"into the test data directory"
)
except (OSError, HTTPException) as exc:
raise unittest.SkipTest(f"Failed to download {TESTDATAURL}: {exc}")


class UnicodeMethodsTest(unittest.TestCase):

# update this, if the database changes
Expand Down Expand Up @@ -651,6 +671,206 @@ def test_east_asian_width_unassigned(self):
self.assertEqual(eaw(char), 'A')
self.assertIs(self.db.name(char, None), None)

def test_grapheme_cluster_break(self):
gcb = self.db._grapheme_cluster_break
self.assertEqual(gcb(' '), 'Other')
self.assertEqual(gcb('x'), 'Other')
self.assertEqual(gcb('\U0010FFFF'), 'Other')
self.assertEqual(gcb('\r'), 'CR')
self.assertEqual(gcb('\n'), 'LF')
self.assertEqual(gcb('\0'), 'Control')
self.assertEqual(gcb('\t'), 'Control')
self.assertEqual(gcb('\x1F'), 'Control')
self.assertEqual(gcb('\x7F'), 'Control')
self.assertEqual(gcb('\x9F'), 'Control')
self.assertEqual(gcb('\U000E0001'), 'Control')
self.assertEqual(gcb('\u0300'), 'Extend')
self.assertEqual(gcb('\u200C'), 'Extend')
self.assertEqual(gcb('\U000E01EF'), 'Extend')
self.assertEqual(gcb('\u1159'), 'L')
self.assertEqual(gcb('\u11F9'), 'T')
self.assertEqual(gcb('\uD788'), 'LV')
self.assertEqual(gcb('\uD7A3'), 'LVT')
# New in 5.0.0
self.assertEqual(gcb('\u05BA'), 'Extend')
self.assertEqual(gcb('\u20EF'), 'Extend')
# New in 5.1.0
self.assertEqual(gcb('\u2064'), 'Control')
self.assertEqual(gcb('\uAA4D'), 'SpacingMark')
# New in 5.2.0
self.assertEqual(gcb('\u0816'), 'Extend')
self.assertEqual(gcb('\uA97C'), 'L')
self.assertEqual(gcb('\uD7C6'), 'V')
self.assertEqual(gcb('\uD7FB'), 'T')
# New in 6.0.0
self.assertEqual(gcb('\u093A'), 'Extend')
self.assertEqual(gcb('\U00011002'), 'SpacingMark')
# New in 6.1.0
self.assertEqual(gcb('\U000E0FFF'), 'Control')
self.assertEqual(gcb('\U00016F7E'), 'SpacingMark')
# New in 6.2.0
self.assertEqual(gcb('\U0001F1E6'), 'Regional_Indicator')
self.assertEqual(gcb('\U0001F1FF'), 'Regional_Indicator')
# New in 6.3.0
self.assertEqual(gcb('\u180E'), 'Control')
self.assertEqual(gcb('\u1A1B'), 'Extend')
# New in 7.0.0
self.assertEqual(gcb('\u0E33'), 'SpacingMark')
self.assertEqual(gcb('\u0EB3'), 'SpacingMark')
self.assertEqual(gcb('\U0001BCA3'), 'Control')
self.assertEqual(gcb('\U0001E8D6'), 'Extend')
self.assertEqual(gcb('\U0001163E'), 'SpacingMark')
# New in 8.0.0
self.assertEqual(gcb('\u08E3'), 'Extend')
self.assertEqual(gcb('\U00011726'), 'SpacingMark')
# New in 9.0.0
self.assertEqual(gcb('\u0600'), 'Prepend')
self.assertEqual(gcb('\U000E007F'), 'Extend')
self.assertEqual(gcb('\U00011CB4'), 'SpacingMark')
self.assertEqual(gcb('\u200D'), 'ZWJ')
# New in 10.0.0
self.assertEqual(gcb('\U00011D46'), 'Prepend')
self.assertEqual(gcb('\U00011D47'), 'Extend')
self.assertEqual(gcb('\U00011A97'), 'SpacingMark')
# New in 11.0.0
self.assertEqual(gcb('\U000110CD'), 'Prepend')
self.assertEqual(gcb('\u07FD'), 'Extend')
self.assertEqual(gcb('\U00011EF6'), 'SpacingMark')
# New in 12.0.0
self.assertEqual(gcb('\U00011A84'), 'Prepend')
self.assertEqual(gcb('\U00013438'), 'Control')
self.assertEqual(gcb('\U0001E2EF'), 'Extend')
self.assertEqual(gcb('\U00016F87'), 'SpacingMark')
# New in 13.0.0
self.assertEqual(gcb('\U00011941'), 'Prepend')
self.assertEqual(gcb('\U00016FE4'), 'Extend')
self.assertEqual(gcb('\U00011942'), 'SpacingMark')
# New in 14.0.0
self.assertEqual(gcb('\u0891'), 'Prepend')
self.assertEqual(gcb('\U0001E2AE'), 'Extend')
# New in 15.0.0
self.assertEqual(gcb('\U00011F02'), 'Prepend')
self.assertEqual(gcb('\U0001343F'), 'Control')
self.assertEqual(gcb('\U0001E4EF'), 'Extend')
self.assertEqual(gcb('\U00011F3F'), 'SpacingMark')
# New in 16.0.0
self.assertEqual(gcb('\U000113D1'), 'Prepend')
self.assertEqual(gcb('\U0001E5EF'), 'Extend')
self.assertEqual(gcb('\U0001612C'), 'SpacingMark')
self.assertEqual(gcb('\U00016D63'), 'V')
self.assertRaises(TypeError, gcb)
self.assertRaises(TypeError, gcb, b'x')
self.assertRaises(TypeError, gcb, 120)
self.assertRaises(TypeError, gcb, '')
self.assertRaises(TypeError, gcb, 'xx')

def test_indic_conjunct_break(self):
incb = self.db._indic_conjunct_break
self.assertEqual(incb(' '), 'None')
self.assertEqual(incb('x'), 'None')
self.assertEqual(incb('\U0010FFFF'), 'None')
# New in 15.1.0
self.assertEqual(incb('\u094D'), 'Linker')
self.assertEqual(incb('\u0D4D'), 'Linker')
self.assertEqual(incb('\u0915'), 'Consonant')
self.assertEqual(incb('\u0D3A'), 'Consonant')
self.assertEqual(incb('\u0300'), 'Extend')
self.assertEqual(incb('\U0001E94A'), 'Extend')
# New in 16.0.0
self.assertEqual(incb('\u034F'), 'Extend')
self.assertEqual(incb('\U000E01EF'), 'Extend')
self.assertRaises(TypeError, incb)
self.assertRaises(TypeError, incb, b'x')
self.assertRaises(TypeError, incb, 120)
self.assertRaises(TypeError, incb, '')
self.assertRaises(TypeError, incb, 'xx')

def test_extended_pictographic(self):
ext_pict = self.db._extended_pictographic
self.assertIs(ext_pict(' '), False)
self.assertIs(ext_pict('x'), False)
self.assertIs(ext_pict('\U0010FFFF'), False)
# New in 13.0.0
self.assertIs(ext_pict('\xA9'), True)
self.assertIs(ext_pict('\u203C'), True)
self.assertIs(ext_pict('\U0001FAD6'), True)
self.assertIs(ext_pict('\U0001FFFD'), True)
self.assertRaises(TypeError, ext_pict)
self.assertRaises(TypeError, ext_pict, b'x')
self.assertRaises(TypeError, ext_pict, 120)
self.assertRaises(TypeError, ext_pict, '')
self.assertRaises(TypeError, ext_pict, 'xx')

def test_grapheme_break(self):
def graphemes(*args):
return list(map(str, self.db._iter_graphemes(*args)))

self.assertRaises(TypeError, self.db._iter_graphemes)
self.assertRaises(TypeError, self.db._iter_graphemes, b'x')
self.assertRaises(TypeError, self.db._iter_graphemes, 'x', 0, 0, 0)

self.assertEqual(graphemes(''), [])
self.assertEqual(graphemes('abcd'), ['a', 'b', 'c', 'd'])
self.assertEqual(graphemes('abcd', 1), ['b', 'c', 'd'])
self.assertEqual(graphemes('abcd', 1, 3), ['b', 'c'])
self.assertEqual(graphemes('abcd', -3), ['b', 'c', 'd'])
self.assertEqual(graphemes('abcd', 1, -1), ['b', 'c'])
self.assertEqual(graphemes('abcd', 3, 1), [])
self.assertEqual(graphemes('abcd', 5), [])
self.assertEqual(graphemes('abcd', 0, 5), ['a', 'b', 'c', 'd'])
self.assertEqual(graphemes('abcd', -5), ['a', 'b', 'c', 'd'])
self.assertEqual(graphemes('abcd', 0, -5), [])
# GB3
self.assertEqual(graphemes('\r\n'), ['\r\n'])
# GB4
self.assertEqual(graphemes('\r\u0308'), ['\r', '\u0308'])
self.assertEqual(graphemes('\n\u0308'), ['\n', '\u0308'])
self.assertEqual(graphemes('\0\u0308'), ['\0', '\u0308'])
# GB5
self.assertEqual(graphemes('\u06dd\r'), ['\u06dd', '\r'])
self.assertEqual(graphemes('\u06dd\n'), ['\u06dd', '\n'])
self.assertEqual(graphemes('\u06dd\0'), ['\u06dd', '\0'])
# GB6
self.assertEqual(graphemes('\u1100\u1160'), ['\u1100\u1160'])
self.assertEqual(graphemes('\u1100\uAC00'), ['\u1100\uAC00'])
self.assertEqual(graphemes('\u1100\uAC01'), ['\u1100\uAC01'])
# GB7
self.assertEqual(graphemes('\uAC00\u1160'), ['\uAC00\u1160'])
self.assertEqual(graphemes('\uAC00\u11A8'), ['\uAC00\u11A8'])
self.assertEqual(graphemes('\u1160\u1160'), ['\u1160\u1160'])
self.assertEqual(graphemes('\u1160\u11A8'), ['\u1160\u11A8'])
# GB8
self.assertEqual(graphemes('\uAC01\u11A8'), ['\uAC01\u11A8'])
self.assertEqual(graphemes('\u11A8\u11A8'), ['\u11A8\u11A8'])
# GB9
self.assertEqual(graphemes('a\u0300'), ['a\u0300'])
self.assertEqual(graphemes('a\u200D'), ['a\u200D'])
# GB9a
self.assertEqual(graphemes('\u0905\u0903'), ['\u0905\u0903'])
# GB9b
self.assertEqual(graphemes('\u06dd\u0661'), ['\u06dd\u0661'])
# GB9c
self.assertEqual(graphemes('\u0915\u094d\u0924'),
['\u0915\u094d\u0924'])
self.assertEqual(graphemes('\u0915\u094D\u094D\u0924'),
['\u0915\u094D\u094D\u0924'])
self.assertEqual(graphemes('\u0915\u094D\u0924\u094D\u092F'),
['\u0915\u094D\u0924\u094D\u092F'])
# GB11
self.assertEqual(graphemes(
'\U0001F9D1\U0001F3FE\u200D\u2764\uFE0F'
'\u200D\U0001F48B\u200D\U0001F9D1\U0001F3FC'),
['\U0001F9D1\U0001F3FE\u200D\u2764\uFE0F'
'\u200D\U0001F48B\u200D\U0001F9D1\U0001F3FC'])
# GB12
self.assertEqual(graphemes(
'\U0001F1FA\U0001F1E6\U0001F1FA\U0001F1F3'),
['\U0001F1FA\U0001F1E6', '\U0001F1FA\U0001F1F3'])
# GB13
self.assertEqual(graphemes(
'a\U0001F1FA\U0001F1E6\U0001F1FA\U0001F1F3'),
['a', '\U0001F1FA\U0001F1E6', '\U0001F1FA\U0001F1F3'])


class Unicode_3_2_0_FunctionsTest(UnicodeFunctionsTest):
db = unicodedata.ucd_3_2_0
Expand All @@ -659,6 +879,11 @@ class Unicode_3_2_0_FunctionsTest(UnicodeFunctionsTest):
if quicktest else
'caf1a7f2f380f927461837f1901ef20683f98683')

test_grapheme_cluster_break = None
test_indic_conjunct_break = None
test_extended_pictographic = None
test_grapheme_break = None


class UnicodeMiscTest(unittest.TestCase):
db = unicodedata
Expand Down Expand Up @@ -761,13 +986,19 @@ def test_linebreak_7643(self):
self.assertEqual(len(lines), 1,
r"%a should not be a linebreak" % c)

def test_segment_object(self):
segments = list(unicodedata._iter_graphemes('spa\u0300m'))
self.assertEqual(len(segments), 4, segments)
segment = segments[2]
self.assertEqual(segment.start, 2)
self.assertEqual(segment.end, 4)
self.assertEqual(str(segment), 'a\u0300')
self.assertEqual(repr(segment), '<Segment 2:4>')
self.assertRaises(TypeError, iter, segment)
self.assertRaises(TypeError, len, segment)

class NormalizationTest(unittest.TestCase):
@staticmethod
def check_version(testfile):
hdr = testfile.readline()
return unicodedata.unidata_version in hdr

class NormalizationTest(unittest.TestCase):
@staticmethod
def unistr(data):
data = [int(x, 16) for x in data.split(" ")]
Expand All @@ -777,17 +1008,7 @@ def unistr(data):
@requires_resource('cpu')
def test_normalization(self):
TESTDATAFILE = "NormalizationTest.txt"
TESTDATAURL = f"http://www.pythontest.net/unicode/{unicodedata.unidata_version}/{TESTDATAFILE}"

# Hit the exception early
try:
testdata = open_urlresource(TESTDATAURL, encoding="utf-8",
check=self.check_version)
except PermissionError:
self.skipTest(f"Permission error when downloading {TESTDATAURL} "
f"into the test data directory")
except (OSError, HTTPException) as exc:
self.skipTest(f"Failed to download {TESTDATAURL}: {exc}")
testdata = download_test_data_file(TESTDATAFILE)

with testdata:
self.run_normalization_tests(testdata, unicodedata)
Expand Down Expand Up @@ -883,5 +1104,46 @@ class MyStr(str):
self.assertIs(type(normalize(form, MyStr(input_str))), str)


class GraphemeBreakTest(unittest.TestCase):
@requires_resource('network')
def test_grapheme_break(self):
TESTDATAFILE = "GraphemeBreakTest.txt"
testdata = download_test_data_file(TESTDATAFILE)

with testdata:
self.run_grapheme_break_tests(testdata)

def run_grapheme_break_tests(self, testdata):
for line in testdata:
line, _, comment = line.partition('#')
line = line.strip()
if not line:
continue
comment = comment.strip()

chunks = []
breaks = []
pos = 0
for field in line.replace('×', ' ').split():
if field == '÷':
chunks.append('')
breaks.append(pos)
else:
chunks[-1] += chr(int(field, 16))
pos += 1
self.assertEqual(chunks.pop(), '', line)
input = ''.join(chunks)
with self.subTest(line):
result = list(unicodedata._iter_graphemes(input))
self.assertEqual(list(map(str, result)), chunks, comment)
self.assertEqual([x.start for x in result], breaks[:-1], comment)
self.assertEqual([x.end for x in result], breaks[1:], comment)
for i in range(1, len(breaks) - 1):
result = list(unicodedata._iter_graphemes(input, breaks[i]))
self.assertEqual(list(map(str, result)), chunks[i:], comment)
self.assertEqual([x.start for x in result], breaks[i:-1], comment)
self.assertEqual([x.end for x in result], breaks[i+1:], comment)


if __name__ == "__main__":
unittest.main()
1 change: 1 addition & 0 deletions Misc/ACKS
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -1656,6 +1656,7 @@ Victor Salgado
Rich Salz
Kevin Samborn
Adrian Sampson
Guillaume Sanchez
Nevada Sanchez
James Sanders
Ilya Sandler
Expand Down
Loading
Loading