bpo-28660: Make TextWrapper break long words on hyphens (GH-22721)
diff --git a/Lib/test/test_textwrap.py b/Lib/test/test_textwrap.py
index ed97f70..dfbc2b9 100644
--- a/Lib/test/test_textwrap.py
+++ b/Lib/test/test_textwrap.py
@@ -640,6 +640,78 @@
max_lines=4)
+class LongWordWithHyphensTestCase(BaseTestCase):
+ def setUp(self):
+ self.wrapper = TextWrapper()
+ self.text1 = '''\
+We used enyzme 2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate synthase.
+'''
+ self.text2 = '''\
+1234567890-1234567890--this_is_a_very_long_option_indeed-good-bye"
+'''
+
+ def test_break_long_words_on_hyphen(self):
+ expected = ['We used enyzme 2-succinyl-6-hydroxy-2,4-',
+ 'cyclohexadiene-1-carboxylate synthase.']
+ self.check_wrap(self.text1, 50, expected)
+
+ expected = ['We used', 'enyzme 2-', 'succinyl-', '6-hydroxy-', '2,4-',
+ 'cyclohexad', 'iene-1-', 'carboxylat', 'e', 'synthase.']
+ self.check_wrap(self.text1, 10, expected)
+
+ expected = ['1234567890', '-123456789', '0--this_is', '_a_very_lo',
+ 'ng_option_', 'indeed-', 'good-bye"']
+ self.check_wrap(self.text2, 10, expected)
+
+ def test_break_long_words_not_on_hyphen(self):
+ expected = ['We used enyzme 2-succinyl-6-hydroxy-2,4-cyclohexad',
+ 'iene-1-carboxylate synthase.']
+ self.check_wrap(self.text1, 50, expected, break_on_hyphens=False)
+
+ expected = ['We used', 'enyzme 2-s', 'uccinyl-6-', 'hydroxy-2,',
+ '4-cyclohex', 'adiene-1-c', 'arboxylate', 'synthase.']
+ self.check_wrap(self.text1, 10, expected, break_on_hyphens=False)
+
+ expected = ['1234567890', '-123456789', '0--this_is', '_a_very_lo',
+ 'ng_option_', 'indeed-', 'good-bye"']
+ self.check_wrap(self.text2, 10, expected)
+
+ def test_break_on_hyphen_but_not_long_words(self):
+ expected = ['We used enyzme',
+ '2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate',
+ 'synthase.']
+
+ self.check_wrap(self.text1, 50, expected, break_long_words=False)
+
+ expected = ['We used', 'enyzme',
+ '2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate',
+ 'synthase.']
+ self.check_wrap(self.text1, 10, expected, break_long_words=False)
+
+ expected = ['1234567890', '-123456789', '0--this_is', '_a_very_lo',
+ 'ng_option_', 'indeed-', 'good-bye"']
+ self.check_wrap(self.text2, 10, expected)
+
+
+ def test_do_not_break_long_words_or_on_hyphens(self):
+ expected = ['We used enyzme',
+ '2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate',
+ 'synthase.']
+ self.check_wrap(self.text1, 50, expected,
+ break_long_words=False,
+ break_on_hyphens=False)
+
+ expected = ['We used', 'enyzme',
+ '2-succinyl-6-hydroxy-2,4-cyclohexadiene-1-carboxylate',
+ 'synthase.']
+ self.check_wrap(self.text1, 10, expected,
+ break_long_words=False,
+ break_on_hyphens=False)
+
+ expected = ['1234567890', '-123456789', '0--this_is', '_a_very_lo',
+ 'ng_option_', 'indeed-', 'good-bye"']
+ self.check_wrap(self.text2, 10, expected)
+
class IndentTestCases(BaseTestCase):
# called before each test method
diff --git a/Lib/textwrap.py b/Lib/textwrap.py
index 30e693c..841de9b 100644
--- a/Lib/textwrap.py
+++ b/Lib/textwrap.py
@@ -215,8 +215,16 @@
# If we're allowed to break long words, then do so: put as much
# of the next chunk onto the current line as will fit.
if self.break_long_words:
- cur_line.append(reversed_chunks[-1][:space_left])
- reversed_chunks[-1] = reversed_chunks[-1][space_left:]
+ end = space_left
+ chunk = reversed_chunks[-1]
+ if self.break_on_hyphens and len(chunk) > space_left:
+ # break after last hyphen, but only if there are
+ # non-hyphens before it
+ hyphen = chunk.rfind('-', 0, space_left)
+ if hyphen > 0 and any(c != '-' for c in chunk[:hyphen]):
+ end = hyphen + 1
+ cur_line.append(chunk[:end])
+ reversed_chunks[-1] = chunk[end:]
# Otherwise, we have to preserve the long word intact. Only add
# it to the current line if there's nothing already there --