Replace and inserting strings within .txt files with the use of regex

John S jstrickler at gmail.com
Sun Aug 8 19:29:16 CEST 2010


On Aug 8, 10:59 am, Thomas Jollans <tho... at jollans.com> wrote:
> On 08/08/2010 04:06 PM, Νίκος wrote:
>
>
>
>
>
> > On 8 Αύγ, 15:40, Thomas Jollans <tho... at jollans.com> wrote:
> >> On 08/08/2010 01:41 PM, Νίκος wrote:
>
> >>> I was so dizzy and confused yesterday that i forgot to metnion that
> >>> not only i need removal of php openign and closing tags but whaevers
> >>> data lurks inside those tags as well ebcause now with the 'counter.py'
> >>> script i wrote the html fiels would open ftm there and substitute the
> >>> tempalte variabels like %(counter)d
>
> >> I could just hand you a solution, but I'll be a bit of a bastard and
> >> just give you some hints.
>
> >> You could use regular expressions. If you know regular expressions, it's
> >> relatively trivial - but I doubt you know regexp.
>
> > Here is the code with some try-and-fail modification i made, still non-
> > working based on your hints:
> > ==========================================================
>
> > id = 0  # unique page_id
>
> > for currdir, files, dirs in os.walk('varsa'):
>
> >     for f in files:
>
> >         if f.endswith('php'):
>
> >             # get abs path to filename
> >             src_f = join(currdir, f)
>
> >             # open php src file
> >             print 'reading from %s' % src_f
> >             f = open(src_f, 'r')
> >             src_data = f.read()         # read contents of PHP file
> >             f.close()
>
> >             # replace tags
> >             print 'replacing php tags and contents within'
> >             src_data = src_data.replace(r'<?.?>', '')             #
> > the dot matches any character i hope! no matter how many of them?!?
>
> Two problems here:
>
> str.replace doesn't use regular expressions. You'll have to use the re
> module to use regexps. (the re.sub function to be precise)
>
> '.'  matches a single character. Any character, but only one.
> '.*' matches as many characters as possible. This is not what you want,
> since it will match everything between the *first* <? and the *last* ?>.
> You want non-greedy matching.
>
> '.*?' is the same thing, without the greed.
>
>
>
> >             # add ID
> >             print 'adding unique page_id'
> >             src_data = ( '<!-- %d -->' % id ) + src_data
> >             id += 1
>
> >             # add template variables
> >             print 'adding counter template variable'
> >             src_data = src_data + ''' <h4><font color=green> Αριθμός
> > Επισκεπτών: %(counter)d </font></h4> '''
> >             # i can think of this but the above line must be above </
> > body></html> NOT after but how to right that?!?
>
> You will have to find the </body> tag before inserting the string.
> str.find should help -- or you could use str.replace and replace the
> </body> tag with you counter line, plus a new </body>.
>
>
>
> >             # rename old php file to new with .html extension
> >             src_file = src_file.replace('.php', '.html')
>
> >             # open newly created html file for inserting data
> >             print 'writing to %s' % dest_f
> >             dest_f = open(src_f, 'w')
> >             dest_f.write(src_data)      # write contents
> >             dest_f.close()
>
> > This is the best i can do.
>
> No it's not. You're just giving up too soon.

When replacing text in an HTML document with re.sub, you want to use
the re.S (singleline) option; otherwise your pattern won't match when
the opening tag is on one line and the closing is on another.



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