How to write Regular Expression for recursive matching? | | |
Hi All,
I have problem to split a string like this:
'abc.defg.hij.klmnop'
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
'abc.defg', 'defg.hij', 'hij.klmnop'
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
is there a way to get 'defg.hij' using regular expression?
Thanks,
| | | | re: How to write Regular Expression for recursive matching?
On Nov 26, 10:40 am, lisong <lisong.1...@gmail.comwrote: Quote:
Hi All,
>
I have problem to split a string like this:
>
'abc.defg.hij.klmnop'
>
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
>
'abc.defg', 'defg.hij', 'hij.klmnop'
>
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
>
is there a way to get 'defg.hij' using regular expression?
>
Thanks,
Why are you using regular expressions? Use the split method defined
for strings: Quote: Quote: Quote:
>>'abc.defg.hij.klmnop'.split('.')
['abc', 'defg', 'hij', 'klmnop']
-- Paul | | | | re: How to write Regular Expression for recursive matching?
lisong wrote: Quote:
Hi All,
>
I have problem to split a string like this:
>
'abc.defg.hij.klmnop'
>
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
>
'abc.defg', 'defg.hij', 'hij.klmnop'
>
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
>
is there a way to get 'defg.hij' using regular expression?
Nope. Regular expressions can't get back in their input-stream, at least not
for such stuff.
The problem at hand is easily solved using
s = 'abc.defg.hij.klmnop'
pairs = [".".join(v) for v in zip(s.split(".")[:-1], s.split(".")[1:])]
Diez | | | | re: How to write Regular Expression for recursive matching?
On Nov 26, 10:51 am, Paul McGuire <pt...@austin.rr.comwrote: Quote:
On Nov 26, 10:40 am, lisong <lisong.1...@gmail.comwrote:
>
>
>
>
> > Quote:
I have problem to split a string like this:
> Quote:
'abc.defg.hij.klmnop'
> Quote:
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
> Quote:
'abc.defg', 'defg.hij', 'hij.klmnop'
> Quote:
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
> Quote:
is there a way to get 'defg.hij' using regular expression?
> >
Why are you using regular expressions? Use the split method defined
for strings:
> Quote: Quote:
>'abc.defg.hij.klmnop'.split('.')
>
['abc', 'defg', 'hij', 'klmnop']
>
-- Paul- Hide quoted text -
>
- Show quoted text -
Sorry, misread your post - Diez Roggisch has the right answer.
-- Paul | | | | re: How to write Regular Expression for recursive matching?
lisong wrote: Quote:
Hi All,
>
I have problem to split a string like this:
>
'abc.defg.hij.klmnop'
>
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
>
'abc.defg', 'defg.hij', 'hij.klmnop'
>
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
>
is there a way to get 'defg.hij' using regular expression?
>
Thanks,
>
Do you need it to be a regular expression ? ws = s.split('.')
return map('.'.join,zip(ws,ws[1:])) Quote: Quote: Quote:
>>f('abc.defg.hij.klmnop')
['abc.defg', 'defg.hij', 'hij.klmnop'] | | | | re: How to write Regular Expression for recursive matching?
On Mon, Nov 26, 2007 at 06:04:54PM +0100, Diez B. Roggisch wrote regarding Re: How to write Regular Expression for recursive matching?: Quote:
>
lisong wrote:
> Quote:
Hi All,
I have problem to split a string like this:
'abc.defg.hij.klmnop'
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
'abc.defg', 'defg.hij', 'hij.klmnop'
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
is there a way to get 'defg.hij' using regular expression?
>
Nope. Regular expressions can't get back in their input-stream, at least not
for such stuff.
>
The problem at hand is easily solved using
>
s = 'abc.defg.hij.klmnop'
>
pairs = [".".join(v) for v in zip(s.split(".")[:-1], s.split(".")[1:])]
>
which is veritably perlesque in its elegance and simplicity!
A slightly more verbose version.
l = s.split('.')
pairs = []
for x in xrange(len(l)-1):
pairs.append('.'.join(l[x:x+2]))
Cheers,
Cliff | | | | re: How to write Regular Expression for recursive matching?
On Nov 26, 12:34 pm, "J. Clifford Dyer" <j...@sdf.lonestar.orgwrote: Quote:
On Mon, Nov 26, 2007 at 06:04:54PM +0100, Diez B. Roggisch wrote regarding Re: How to write Regular Expression for recursive matching?:
>
>
>
>
> > > Quote: Quote:
I have problem to split a string like this:
> Quote: Quote:
'abc.defg.hij.klmnop'
> Quote: Quote:
and I want to get all substrings with only one '.' in mid. so the
output I expect is :
> Quote: Quote:
'abc.defg', 'defg.hij', 'hij.klmnop'
> Quote: Quote:
a simple regular expression '\w+.\w' will only return:
'abc.defg', 'hij.klmnop'
> Quote: Quote:
is there a way to get 'defg.hij' using regular expression?
> Quote:
Nope. Regular expressions can't get back in their input-stream, at least not
for such stuff.
> Quote:
The problem at hand is easily solved using
> Quote:
s = 'abc.defg.hij.klmnop'
> Quote:
pairs = [".".join(v) for v in zip(s.split(".")[:-1], s.split(".")[1:])]
>
which is veritably perlesque in its elegance and simplicity!
>
A slightly more verbose version.
>
l = s.split('.')
pairs = []
for x in xrange(len(l)-1):
pairs.append('.'.join(l[x:x+2]))
>
Cheers,
Cliff
Thank u all for your kindly reply, I agree, RE is not necessary here.
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