Re: Quickie - Regexp for a string not at the beginning of the line
On Fri, Oct 26, 2012 at 8:32 AM, Ed Morton wrote:
> On 10/25/2012 11:45 PM, Rivka Miller wrote:
>>
>> Thanks everyone, esp this gentleman.
>>
>> The solution that worked best for me is just to use a DOT before the
>> string as the one at the beginning of the line did not have any char
>> before it.
>
>
> That's fine but do you understand that that is not an RE that matches on
> "$hello$ not at the start of a line", it's an RE that matches on " char>$hello$ anywhere in the line"? There's a difference - if you use a tool
> that prints the text that matches an RE then the output if the first RE
> existed would be "$hello$" while the output for the second RE would be
> "X$hello$" or "Y$hello$" or
>
> In some tools you can use /(.)$hello$/ or similar to ignore the first part
> of the RE "(.)" and just print the second "$hello", but that ability and
> it's syntax is tool-specific, you still can't say "here's an RE that does
> this", you've got to say "here's how to find this text using tool
> ".
>
>Ed.
>
>
>> I guess, this requires the ability to ignore the CARAT as the beginning of
>> the line.
>>
>> I am a satisfied custormer. No need for returns. :)
>>
>> On Oct 25, 7:11 pm, Ben Bacarisse wrote:
>>>
>>> Rivka Miller writes:
On Oct 25, 2:27 pm, Danny wrote:
>
> Why you just don't give us the string/input, say a line or two, and
> what you want off of it, so we can tell better what to suggest
>>>
>>>
no one has really helped yet.
>>>
>>>
>>> Really? I was going to reply but then I saw Janis had given you the
>>> answer. If it's not the answer, you should just reply saying what it is
>>> that's wrong with it.
>>>
I want to search and modify.
>>>
>>>
>>> Ah. That was missing from the original post. You can't expect people
>>> to help with questions that weren't asked! To replace you will usually
>>> have to capture the single preceding character. E.g. in sed:
>>>
>>>sed -e 's/\(.\)$hello\$/\1XXX/'
>>>
>>> but some RE engines (Perl's, for example) allow you specify zero-width
>>> assertions. You could, in Perl, write
>>>
>>>s/(?<=.)\$hello\$/XXX/
>>>
>>> without having to capture whatever preceded the target string. But
>>> since Perl also has negative zero-width look-behind you can code your
>>> request even more directly:
>>>
>>>s/(?>>
I dont wanna be tied to a specific language etc so I just want a
regexp and as many versions as possible. Maybe I should try in emacs
and so I am now posting to emacs groups also, although javascript has
rich set of regexp facilities.
>>>
>>>
>>> You can't always have a universal solution because different PE
>>> implementations have different syntax and semantics, but you should be
>>> able to translate Janis's solution of matching *something* before your
>>> target into every RE implementation around.
>>>
examples
>>>
>>>
$hello$ should not be selected but
not hello but all of the $hello$ and $hello$ ... $hello$ each one
selected
>>>
>>>
>>> I have taken your $s to be literal. That's not 100 obvious since $ is a
>>> common (universal?) RE meta-character.
>>>
>>>
>>> --
>>> Ben.
>>
>>
>
> --
> http://mail.python.org/mailman/listinfo/python-list
I would use str.find('your string')
It returns -1 if not found, and the index if it finds it.
why use regex for this?
--
Joel Goldstick
--
http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On 10/25/2012 11:45 PM, Rivka Miller wrote: Thanks everyone, esp this gentleman. The solution that worked best for me is just to use a DOT before the string as the one at the beginning of the line did not have any char before it. That's fine but do you understand that that is not an RE that matches on "$hello$ not at the start of a line", it's an RE that matches on "char>$hello$ anywhere in the line"? There's a difference - if you use a tool that prints the text that matches an RE then the output if the first RE existed would be "$hello$" while the output for the second RE would be "X$hello$" or "Y$hello$" or In some tools you can use /(.)$hello$/ or similar to ignore the first part of the RE "(.)" and just print the second "$hello", but that ability and it's syntax is tool-specific, you still can't say "here's an RE that does this", you've got to say "here's how to find this text using tool ". Ed. I guess, this requires the ability to ignore the CARAT as the beginning of the line. I am a satisfied custormer. No need for returns. :) On Oct 25, 7:11 pm, Ben Bacarisse wrote: Rivka Miller writes: On Oct 25, 2:27 pm, Danny wrote: Why you just don't give us the string/input, say a line or two, and what you want off of it, so we can tell better what to suggest no one has really helped yet. Really? I was going to reply but then I saw Janis had given you the answer. If it's not the answer, you should just reply saying what it is that's wrong with it. I want to search and modify. Ah. That was missing from the original post. You can't expect people to help with questions that weren't asked! To replace you will usually have to capture the single preceding character. E.g. in sed: sed -e 's/\(.\)$hello\$/\1XXX/' but some RE engines (Perl's, for example) allow you specify zero-width assertions. You could, in Perl, write s/(?<=.)\$hello\$/XXX/ without having to capture whatever preceded the target string. But since Perl also has negative zero-width look-behind you can code your request even more directly: s/(? I dont wanna be tied to a specific language etc so I just want a regexp and as many versions as possible. Maybe I should try in emacs and so I am now posting to emacs groups also, although javascript has rich set of regexp facilities. You can't always have a universal solution because different PE implementations have different syntax and semantics, but you should be able to translate Janis's solution of matching *something* before your target into every RE implementation around. examples $hello$ should not be selected but not hello but all of the $hello$ and $hello$ ... $hello$ each one selected I have taken your $s to be literal. That's not 100 obvious since $ is a common (universal?) RE meta-character. -- Ben. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
Rivka Miller writes: > Thanks everyone, esp this gentleman. Kind of you to single me out, but it was Janis Papanagnou who first posted the solution that you say "works best" for you. -- Ben. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
Rivka Miller wrote: > I am looking for a regexp for a string not at the beginning of the > line. > > For example, I want to find $hello$ that does not occur at the > beginning of the string, ie all $hello$ that exclude ^$hello$. The begging of the string is zero width character. So you could use negative lookahead (?!^). Then the regular expression looks like: /(?!^)\$hello\$/g var str = '$hello$ should not be selected but', str1 = 'not hello but all of the $hello$ and $hello$ ... $hello$ each one '; str.match(/(?!^)\$hello\$/g); //null str1.match(/(?!^)\$hello\$/g); //["$hello$", "$hello$", "$hello$"] -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
Am 26.10.2012 06:45, schrieb Rivka Miller: Thanks everyone, esp this gentleman. Who is "this"? The solution that worked best for me is just to use a DOT before the string as the one at the beginning of the line did not have any char before it. Which was what I suggested, and where you rudely answered... no one has really helped yet. And obviously... I am a satisfied custormer. ...your perception about yourself and about the role of us Usenet posters seems also not be very sane. Good luck. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On Thu, Oct 25, 2012 at 10:00 PM, Ed Morton wrote: > Because there is no solution - there IS no _RE_ that will match a string not > at the beginning of a line. Depending on what the OP meant, the following would both work: - r"^(?!mystring)" (the string does not occur at the beginning) - r"(?!^)mystring" (the string occurs elsewhere than the beginning) [Someone else's interpretation] Both are "regular expressions" even in the academic sense, or else have a translation as regular expressions in the academic sense. They're also Python regexps. So I don't know what you mean. -- Devin -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
Thanks everyone, esp this gentleman. The solution that worked best for me is just to use a DOT before the string as the one at the beginning of the line did not have any char before it. I guess, this requires the ability to ignore the CARAT as the beginning of the line. I am a satisfied custormer. No need for returns. :) On Oct 25, 7:11 pm, Ben Bacarisse wrote: > Rivka Miller writes: > > On Oct 25, 2:27 pm, Danny wrote: > >> Why you just don't give us the string/input, say a line or two, and > >> what you want off of it, so we can tell better what to suggest > > > no one has really helped yet. > > Really? I was going to reply but then I saw Janis had given you the > answer. If it's not the answer, you should just reply saying what it is > that's wrong with it. > > > I want to search and modify. > > Ah. That was missing from the original post. You can't expect people > to help with questions that weren't asked! To replace you will usually > have to capture the single preceding character. E.g. in sed: > > sed -e 's/\(.\)$hello\$/\1XXX/' > > but some RE engines (Perl's, for example) allow you specify zero-width > assertions. You could, in Perl, write > > s/(?<=.)\$hello\$/XXX/ > > without having to capture whatever preceded the target string. But > since Perl also has negative zero-width look-behind you can code your > request even more directly: > > s/(? > > I dont wanna be tied to a specific language etc so I just want a > > regexp and as many versions as possible. Maybe I should try in emacs > > and so I am now posting to emacs groups also, although javascript has > > rich set of regexp facilities. > > You can't always have a universal solution because different PE > implementations have different syntax and semantics, but you should be > able to translate Janis's solution of matching *something* before your > target into every RE implementation around. > > > examples > > > $hello$ should not be selected but > > not hello but all of the $hello$ and $hello$ ... $hello$ each one > > selected > > I have taken your $s to be literal. That's not 100 obvious since $ is a > common (universal?) RE meta-character. > > > -- > Ben. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On Thu, 25 Oct 2012 18:08:53 -0700 (PDT), Rivka Miller wrote in <73f60cf3-d932-4366-a405-676748856...@q16g2000yqc.googlegroups.com>: >no one has really helped yet. We regret that you are not a satisfied customer. Please take your receipt to the cashier and you will receive double your money back according to our "you must be satisfied" guarantee. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On Thu, Oct 25, 2012 at 9:08 PM, Rivka Miller wrote: > On Oct 25, 2:27 pm, Danny wrote: >> Why you just don't give us the string/input, say a line or two, and what you >> want off of it, so we can tell better what to suggest > > no one has really helped yet. > > I want to search and modify. > > I dont wanna be tied to a specific language etc so I just want a > regexp and as many versions as possible. If you just find the one command line app that will perform the task, like awk, then the other languages you will just need to call the commandline function, and return the output from awk. -- Best Regards, David Hutto CEO: http://www.hitwebdevelopment.com -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On 25/10/2012 21:53, Rivka Miller wrote:
Hello Programmers,
I am looking for a regexp for a string not at the beginning of the
line.
Why bother with a silly regex thingy when simple string methods will
suffice e.g.
'yourstring'.find('xyz', 1)
or
'yourstring'.index('xyz', 1)
or
'xyz' in 'yourstring'[1:]
--
Cheers.
Mark Lawrence.
--
http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
Rivka Miller writes: > On Oct 25, 2:27 pm, Danny wrote: >> Why you just don't give us the string/input, say a line or two, and >> what you want off of it, so we can tell better what to suggest > > no one has really helped yet. Really? I was going to reply but then I saw Janis had given you the answer. If it's not the answer, you should just reply saying what it is that's wrong with it. > I want to search and modify. Ah. That was missing from the original post. You can't expect people to help with questions that weren't asked! To replace you will usually have to capture the single preceding character. E.g. in sed: sed -e 's/\(.\)$hello\$/\1XXX/' but some RE engines (Perl's, for example) allow you specify zero-width assertions. You could, in Perl, write s/(?<=.)\$hello\$/XXX/ without having to capture whatever preceded the target string. But since Perl also has negative zero-width look-behind you can code your request even more directly: s/(? I dont wanna be tied to a specific language etc so I just want a > regexp and as many versions as possible. Maybe I should try in emacs > and so I am now posting to emacs groups also, although javascript has > rich set of regexp facilities. You can't always have a universal solution because different PE implementations have different syntax and semantics, but you should be able to translate Janis's solution of matching *something* before your target into every RE implementation around. > examples > > $hello$ should not be selected but > not hello but all of the $hello$ and $hello$ ... $hello$ each one > selected I have taken your $s to be literal. That's not 100 obvious since $ is a common (universal?) RE meta-character. -- Ben. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On 2012-10-26 02:08, Rivka Miller wrote: On Oct 25, 2:27 pm, Danny wrote: Why you just don't give us the string/input, say a line or two, and what you want off of it, so we can tell better what to suggest no one has really helped yet. I want to search and modify. I dont wanna be tied to a specific language etc so I just want a regexp and as many versions as possible. Maybe I should try in emacs and so I am now posting to emacs groups also, although javascript has rich set of regexp facilities. examples $hello$ should not be selected but not hello but all of the $hello$ and $hello$ ... $hello$ each one selected [snip] To match the literal "$hello$" except at the start of a line, use: (?http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On 10/25/2012 8:08 PM, Rivka Miller wrote:
On Oct 25, 2:27 pm, Danny wrote:
Why you just don't give us the string/input, say a line or two, and what you
want off of it, so we can tell better what to suggest
no one has really helped yet.
Because there is no solution - there IS no _RE_ that will match a string not at
the beginning of a line.
Now if you want to know how to extract a string that matches an RE in awk,
that'd be (just one way):
awk 'match($0,/.[$]hello[$]/) { print substr($0,RSTART+1,RLENGTH-1) }'
and other tools would have their ways of producing the same output, but that's
not the question you're asking.
Ed.
I want to search and modify.
I dont wanna be tied to a specific language etc so I just want a
regexp and as many versions as possible. Maybe I should try in emacs
and so I am now posting to emacs groups also, although javascript has
rich set of regexp facilities.
examples
$hello$ should not be selected but
not hello but all of the $hello$ and $hello$ ... $hello$ each one
selected
=
original post
=
Hello Programmers,
I am looking for a regexp for a string not at the beginning of the
line.
For example, I want to find $hello$ that does not occur at the
beginning of the string, ie all $hello$ that exclude ^$hello$.
In addition, if you have a more difficult problem along the same
lines, I would appreciate it. For a single character, eg < not at the
beginning of the line, it is easier, ie
^[^<]+<
but I cant use the same method for more than one character string as
permutation is present and probably for more than one occurrence,
greedy or non-greedy version of [^<]+ would pick first or last but not
the middle ones, unless I break the line as I go and use the non-
greedy version of +. I do have the non-greedy version available, but
what if I didnt?
If you cannot solve the problem completely, just give me a quick
solution with the first non beginning of the line and I will go from
there as I need it in a hurry.
Thanks
--
http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On 10/25/2012 09:08 PM, Rivka Miller wrote: > On Oct 25, 2:27 pm, Danny wrote: >> Why you just don't give us the string/input, say a line or two, and what you >> want off of it, so we can tell better what to suggest > no one has really helped yet. > > > > first non beginning of the line and I will go from > there as I need it in a hurry. > > Call a tow truck and tell him to jump your spare tire from his left turn signal. That'll be about as effective. But crying wolf to several towns at once is probably a mistake. -- DaveA -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On Oct 25, 2:27 pm, Danny wrote: > Why you just don't give us the string/input, say a line or two, and what you > want off of it, so we can tell better what to suggest no one has really helped yet. I want to search and modify. I dont wanna be tied to a specific language etc so I just want a regexp and as many versions as possible. Maybe I should try in emacs and so I am now posting to emacs groups also, although javascript has rich set of regexp facilities. examples $hello$ should not be selected but not hello but all of the $hello$ and $hello$ ... $hello$ each one selected = original post = Hello Programmers, I am looking for a regexp for a string not at the beginning of the line. For example, I want to find $hello$ that does not occur at the beginning of the string, ie all $hello$ that exclude ^$hello$. In addition, if you have a more difficult problem along the same lines, I would appreciate it. For a single character, eg < not at the beginning of the line, it is easier, ie ^[^<]+< but I cant use the same method for more than one character string as permutation is present and probably for more than one occurrence, greedy or non-greedy version of [^<]+ would pick first or last but not the middle ones, unless I break the line as I go and use the non- greedy version of +. I do have the non-greedy version available, but what if I didnt? If you cannot solve the problem completely, just give me a quick solution with the first non beginning of the line and I will go from there as I need it in a hurry. Thanks -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
: On 25 October 2012 16:53, Rivka Miller wrote: > I am looking for a regexp for a string not at the beginning of the > line. There are probably quite a few ways to do this, but '(?>> pattern = re.compile(r"(?>> re.findall(pattern, "this is some text") ['is', 'some', 'text'] -[]z. -- http://mail.python.org/mailman/listinfo/python-list
Re: Quickie - Regexp for a string not at the beginning of the line
On 25.10.2012 22:53, Rivka Miller wrote: > Hello Programmers, > > I am looking for a regexp for a string not at the beginning of the > line. > > For example, I want to find $hello$ that does not occur at the > beginning of the string, ie all $hello$ that exclude ^$hello$. .hello The dot represents any character. But for specific strings that needs adjustments (e.g. looking for hh not at the beginning of a line would require something like ^[^h]+hh - ah, well, you wrote something similar below). Janis > > In addition, if you have a more difficult problem along the same > lines, I would appreciate it. For a single character, eg < not at the > beginning of the line, it is easier, ie > > ^[^<]+< > > but I cant use the same method for more than one character string as > permutation is present and probably for more than one occurrence, > greedy or non-greedy version of [^<]+ would pick first or last but not > the middle ones, unless I break the line as I go and use the non- > greedy version of +. I do have the non-greedy version available, but > what if I didnt? > > If you cannot solve the problem completely, just give me a quick > solution with the first non beginning of the line and I will go from > there as I need it in a hurry. > > Thanks > > -- http://mail.python.org/mailman/listinfo/python-list
Quickie - Regexp for a string not at the beginning of the line
Hello Programmers, I am looking for a regexp for a string not at the beginning of the line. For example, I want to find $hello$ that does not occur at the beginning of the string, ie all $hello$ that exclude ^$hello$. In addition, if you have a more difficult problem along the same lines, I would appreciate it. For a single character, eg < not at the beginning of the line, it is easier, ie ^[^<]+< but I cant use the same method for more than one character string as permutation is present and probably for more than one occurrence, greedy or non-greedy version of [^<]+ would pick first or last but not the middle ones, unless I break the line as I go and use the non- greedy version of +. I do have the non-greedy version available, but what if I didnt? If you cannot solve the problem completely, just give me a quick solution with the first non beginning of the line and I will go from there as I need it in a hurry. Thanks -- http://mail.python.org/mailman/listinfo/python-list
