[Python-bugs-list] [ python-Bugs-595350 ] string method bugs w/ 8bit, unicode args
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Fri, 23 Aug 2002 03:06:56 -0700
Bugs item #595350, was opened at 2002-08-15 01:56
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Category: Unicode
Group: Python 2.3
Status: Open
Resolution: Rejected
Priority: 5
Submitted By: Inyeol Lee (inyeol)
Assigned to: Guido van Rossum (gvanrossum)
Summary: string method bugs w/ 8bit, unicode args
Initial Comment:
Python 2.2.1 (#1, Apr 10 2002, 18:25:16)
[GCC 2.95.3 20010315 (release)] on sunos5
1. "abc".endswith("c") ->1
"abc".endswith(u"c") -> 0 # bug.
u"abc".endswith("c") -> 1
u"abc".endswith(u"c") -> 1
2. "aaa".rfind("a") -> 2
"aaa".rfind(u"a") -> 0 # bug.
u"aaa".rfind("a") -> 2
u"aaa".rfind(u"a") -> 2
.rindex() has the same bug.
3. "abc".rfind("") -> 3
"abc".rfind(u"") -> 0 # bug.
u"abc".rfind("") -> 0 # bug.
u"abc".rfind(u"") -> 0 # bug.
.rindex() has the same bug.
4. "abc".replace("", "x") -> ValueError
"abc".replace(u"", "x") -> u'abcxxxx' # bug.
u"abc".replace("", "x") -> u'abcxxxx' # bug.
u"abc".replace(u"", "x") -> u'abcxxxx' # bug.
They should raise ValueError, or return u'xaxbxcx'.
BTW, how about changing s.replace("") behavior to
return
"xaxbxcx" (or u"xaxbxcx") for all 4 cases? It is
consistent
with other string methods and re.sub() method.
It seems that Guido doesn't mind changing this.
[Guido]
> If someone really wants 'abc'.replace('', '-') to
return '-a-b-c-',
> please submit patches for both 8-bit and Unicode
strings to
> SourceForge and assign to me. I looked into this and
it's
> non-trivial: the implementation used for 8-bit
strings goes into an
> infinite loop when the pattern is empty, and the
Unicode
> implementation tacks '----' onto the end. Please
supply doc and
> unittest patches too. At least re does the right
thing already:
5. (it's not a bug)
Except for .replace() above, s.split() is the only
string method
which raises exception. How about changing this to
return
unmodified string when empty string is given as a
separator?
This is consistent with re.split() behavior.
- Inyeol Lee
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>Comment By: Inyeol Lee (inyeol)
Date: 2002-08-23 10:06
Message:
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bug fixed.
I think we don't need to update .replace() documentation.
I checked latest doc on string methods, such as .count() or
.find(),
still there's no coment on empty string behavior for other
methods.
----------------------------------------------------------------------
Comment By: Guido van Rossum (gvanrossum)
Date: 2002-08-22 15:52
Message:
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Hrm. You uploaded a gzipped tarball containing 5 separate
context diff files; and these were reverse diffs (created by
doing "diff -c new old). I prefer a single file containing
multiple forward context diffs. I've uploaded your patch in
the form that I'd like to see (taken relative to current CVS).
But there's a worse problem: your code contains a bug.
Consider this example:
u'abc'.replace('', '-', 0)
This correctly returns u'abc'.
Bot now try this:
class U(unicode): pass
U(u'abc').replace('', '-', 0)
This returns u'-ab' !!!
Please fix this.
I'm also still waiting for a documentation update.
----------------------------------------------------------------------
Comment By: Inyeol Lee (inyeol)
Date: 2002-08-20 23:54
Message:
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s.replace() patched, unittest updated from current CVS.
Tested with 2.2.1, but it should work fine with 2.3a, since
the codes
affected by this patch didn't changed since 2.2.1.
----------------------------------------------------------------------
Comment By: Guido van Rossum (gvanrossum)
Date: 2002-08-20 17:33
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Note: I've now applied your fixes for endswith and rfind
c.s. to Python 2.2 and 2.3.
----------------------------------------------------------------------
Comment By: Guido van Rossum (gvanrossum)
Date: 2002-08-20 16:35
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I'm rejecting this patch.
The fixes for endswith(), rfind() and rindex() are already
in 2.3; these should be backported to 2.2 and I may use your
code for them.
I can't accept the new feature for replace() until you also
have a working patch for Unicode; I'm only +0 on this so I'm
not going to spend more time getting it right. Feel free to
submit a patch for *just* that here.
I don't want to accept the new feature for split(), because
I disagree that 'abc'.split('') should return ['abc']; if
anything, it should return ['', 'a', 'b', 'c', ''], but one
can argue about this and I think the ValueError is better.
----------------------------------------------------------------------
Comment By: Guido van Rossum (gvanrossum)
Date: 2002-08-19 22:08
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I'm still reviewing this.
Next time, please send context diffs; diffs relative to
current (or at least fairly recent :-) CVS would also be
appreciated.
Don't add the bug number in comments for each change; I will
have to remove all those manually now...
I'm uploading a version patch that applies cleanly to
current CVS; it's not ready yet (the Unicode tests fail and
I have to clean up the comments).
Backporting will be a bitch, because I don't want the
changes for x.replace('', ...) to be backported (new
functionality etc.).
----------------------------------------------------------------------
Comment By: Inyeol Lee (inyeol)
Date: 2002-08-16 17:45
Message:
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uploaded patch for these bugs. -Inyeol Lee
----------------------------------------------------------------------
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