I'm still against actually. That's why the patch hasn't been applied yet. On 10/1/07, Steven Bethard wrote:

On 10/1/07, Clark Maurer wrote:

...

The current implementation doesn't allow for a trailing backslash in the string.

I believe that will change in Python 3.0.

The discussion is here: http://mail.python.org/pipermail/python-3000/2007-May/007684.html

And Ron Adam's current patch is here: http://bugs.python.org/issue1720390

STeVe -- I'm not *in*-sane. Indeed, I am so far *out* of sane that you appear a tiny blip on the distant coast of sanity. --- Bucky Katt, Get Fuzzy _______________________________________________ Python-ideas mailing list Python-ideas@python.org http://mail.python.org/mailman/listinfo/python-ideas

-- --Guido van Rossum (home page: http://www.python.org/~guido/)

On 10/1/07, Steven Bethard wrote:

...

On 10/1/07, Steven Bethard wrote:

...

On 10/1/07, Clark Maurer wrote:

...

The current implementation doesn't allow for a trailing backslash in the string.

I believe that will change in Python 3.0.

The discussion is here: http://mail.python.org/pipermail/python-3000/2007-May/007684.html

And Ron Adam's current patch is here: http://bugs.python.org/issue1720390

On 10/1/07, Guido van Rossum wrote:

...

I'm still against actually. That's why the patch hasn't been applied yet.

Sorry, my mistake. I read the thread as being somewhat in support of the change.

I admit I've been wobbling a lot on this.

Anyway, to the OP, if you want to make this happen, you should help Ron out with his patch. (Code has a much better chance of convincing Guido than anything else does.)

Not in this case. It's more the philosophical distinction -- are raw strings meant primarily to hold regexes or Windows pathnames? These two use cases have opposite requirements for trailing backslash treatment. I know the original use case that caused them to be added to the language is regexes, and that's still the only one I use on a regular basis. -- --Guido van Rossum (home page: http://www.python.org/~guido/)

Oleg Broytmann wrote:

Then just rename them to "regex-strings"; prefix 'r' is stll ok. ;)

But then all the Perl-heads will complain that they don't automatically get compiled into regex objects... -- Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | Carpe post meridiem! | Christchurch, New Zealand | (I'm not a morning person.) | greg.ewing@canterbury.ac.nz +--------------------------------------+

Steven Bethard wrote:

I write quite a few Windows paths, and probably make the final-backslash mistake once a week.

If you were using os.path.join(), as you should be, you wouldn't ever have to write a trailing backslash in a path in the first place. Or any backslashes at all, for that matter. -- Greg Ewing, Computer Science Dept, +--------------------------------------+ University of Canterbury, | Carpe post meridiem! | Christchurch, New Zealand | (I'm not a morning person.) | greg.ewing@canterbury.ac.nz +--------------------------------------+

On Tue, Oct 02, 2007, Greg Ewing wrote:

Steven Bethard wrote:

...

I write quite a few Windows paths, and probably make the final-backslash mistake once a week.

If you were using os.path.join(), as you should be, you wouldn't ever have to write a trailing backslash in a path in the first place. Or any backslashes at all, for that matter.

Wrong. And I just got bitten by this yesterday (no backslashes at all). Consider the difference between cp -a foo bar and cp -a foo/ bar The two are almost identical *except* when foo is a symlink to a directory, then the first form copies the symlink instead of giving a brand-new directory. Which, since foo/ is a template dir that gets modified after copying was a very bad thing. (We moved servers around over the weekend and for convenience's sake made foo a symlink to a new location.) And yes, we *were* using os.path.join(). So trailing slashes (or backslashes) are in fact sometimes required. -- Aahz (aahz@pythoncraft.com) <*> http://www.pythoncraft.com/ The best way to get information on Usenet is not to ask a question, but to post the wrong information.

Aahz wrote:

cp -a foo bar

and

cp -a foo/ bar

The two are almost identical *except* when foo is a symlink to a directory,

Hm. I would call this a misfeature of the version of cp you're using. In Unix, a trailing slash is *never* supposed to be significant. -- Greg

On 10/1/07, Guido van Rossum wrote:

Not in this case. It's more the philosophical distinction -- are raw strings meant primarily to hold regexes or Windows pathnames? These two use cases have opposite requirements for trailing backslash treatment. I know the original use case that caused them to be added to the language is regexes, and that's still the only one I use on a regular basis.

From a teaching (and simplicity) viewpoint, having these be "raw strings" instead of "regexp strings" would be better. The current behavior is a snag I always have to mention when teaching Python, and students are often caught by this once or twice.

As for my experience with regexps, the current behavior is only useful when using both single and double quotes in a single regexp string; I can't recall when I last did so. On 10/1/07, Clark Maurer wrote:

Two quotes should be one single quote. Otherwise, specifying both quote characters in regexes is an issue.

From the teaching point of view, the preferred behavior for "raw strings" would be no escaping for quotes - make them escape-less, period. Mixing single and double quotes would be done by concatenating strings. With Python's terse string concatenation I don't see the need for special escaping for only one character to support a rare use case.

- Tal

On 10/1/07, Steven Bethard wrote:

On 10/1/07, Tal Einat wrote:

...

As for my experience with regexps, the current behavior is only useful when using both single and double quotes in a single regexp string; I can't recall when I last did so.

I have seen regular expressions that look for a double-quoted string which might contain an apostrophe, but don't remember writing one. Other than that, I can't remember *ever* needing to unless I was really (at some level) saying "either of these two"; I also can't remember doing it without being annoyed at having to figure out how many ticks were there, and whether it was double-single or three singles, or what. For me, usability and readability would both improve by offering a named special character, such as \q.

...

From the teaching point of view, the preferred behavior for "raw strings" would be no escaping for quotes - make them escape-less, period.

Exactly my feeling. Thanks for putting it so clearly. =)

Agreed. And also from a "what do *I* have to remember", or a "how does this interact when it gets passed to something else" perspective, because it would remove one level of escaping. -jJ