Bug #1361643: fix textwrap.dedent() so it handles tabs appropriately,
i.e. do *not* expand tabs, but treat them as whitespace that is not
equivalent to spaces. Add a couple of test cases. Clarify docs.
diff --git a/Lib/test/test_textwrap.py b/Lib/test/test_textwrap.py
index 68e4d6d..98cc869 100644
--- a/Lib/test/test_textwrap.py
+++ b/Lib/test/test_textwrap.py
@@ -460,38 +460,42 @@
# of IndentTestCase!
class DedentTestCase(unittest.TestCase):
+ def assertUnchanged(self, text):
+ """assert that dedent() has no effect on 'text'"""
+ self.assertEquals(text, dedent(text))
+
def test_dedent_nomargin(self):
# No lines indented.
text = "Hello there.\nHow are you?\nOh good, I'm glad."
- self.assertEquals(dedent(text), text)
+ self.assertUnchanged(text)
# Similar, with a blank line.
text = "Hello there.\n\nBoo!"
- self.assertEquals(dedent(text), text)
+ self.assertUnchanged(text)
# Some lines indented, but overall margin is still zero.
text = "Hello there.\n This is indented."
- self.assertEquals(dedent(text), text)
+ self.assertUnchanged(text)
# Again, add a blank line.
text = "Hello there.\n\n Boo!\n"
- self.assertEquals(dedent(text), text)
+ self.assertUnchanged(text)
def test_dedent_even(self):
# All lines indented by two spaces.
text = " Hello there.\n How are ya?\n Oh good."
expect = "Hello there.\nHow are ya?\nOh good."
- self.assertEquals(dedent(text), expect)
+ self.assertEquals(expect, dedent(text))
# Same, with blank lines.
text = " Hello there.\n\n How are ya?\n Oh good.\n"
expect = "Hello there.\n\nHow are ya?\nOh good.\n"
- self.assertEquals(dedent(text), expect)
+ self.assertEquals(expect, dedent(text))
# Now indent one of the blank lines.
text = " Hello there.\n \n How are ya?\n Oh good.\n"
expect = "Hello there.\n\nHow are ya?\nOh good.\n"
- self.assertEquals(dedent(text), expect)
+ self.assertEquals(expect, dedent(text))
def test_dedent_uneven(self):
# Lines indented unevenly.
@@ -505,18 +509,53 @@
while 1:
return foo
'''
- self.assertEquals(dedent(text), expect)
+ self.assertEquals(expect, dedent(text))
# Uneven indentation with a blank line.
text = " Foo\n Bar\n\n Baz\n"
expect = "Foo\n Bar\n\n Baz\n"
- self.assertEquals(dedent(text), expect)
+ self.assertEquals(expect, dedent(text))
# Uneven indentation with a whitespace-only line.
text = " Foo\n Bar\n \n Baz\n"
expect = "Foo\n Bar\n\n Baz\n"
- self.assertEquals(dedent(text), expect)
+ self.assertEquals(expect, dedent(text))
+ # dedent() should not mangle internal tabs
+ def test_dedent_preserve_internal_tabs(self):
+ text = " hello\tthere\n how are\tyou?"
+ expect = "hello\tthere\nhow are\tyou?"
+ self.assertEquals(expect, dedent(text))
+
+ # make sure that it preserves tabs when it's not making any
+ # changes at all
+ self.assertEquals(expect, dedent(expect))
+
+ # dedent() should not mangle tabs in the margin (i.e.
+ # tabs and spaces both count as margin, but are *not*
+ # considered equivalent)
+ def test_dedent_preserve_margin_tabs(self):
+ text = " hello there\n\thow are you?"
+ self.assertUnchanged(text)
+
+ # same effect even if we have 8 spaces
+ text = " hello there\n\thow are you?"
+ self.assertUnchanged(text)
+
+ # dedent() only removes whitespace that can be uniformly removed!
+ text = "\thello there\n\thow are you?"
+ expect = "hello there\nhow are you?"
+ self.assertEquals(expect, dedent(text))
+
+ text = " \thello there\n \thow are you?"
+ self.assertEquals(expect, dedent(text))
+
+ text = " \t hello there\n \t how are you?"
+ self.assertEquals(expect, dedent(text))
+
+ text = " \thello there\n \t how are you?"
+ expect = "hello there\n how are you?"
+ self.assertEquals(expect, dedent(text))
def test_main():