Le samedi 27 décembre 2008 à 14:55 -0500, Matt Herzog a écrit :
> On Wed, Dec 24, 2008 at 01:12:55AM -0000, Alan Gauld wrote:
> >
> > "Kent Johnson" <[email protected]> wrote
> >
> > >> for filename in os.listdir(directory):
> > >> result = re.match(s, filename)
> > >> print result
> > >
> > >You never open and read the files. You are searching for the pattern
> > >in the filename, not in the contents of the file.
> >
> > Also note that match() only searches starting at the start of the
> > string.
> >
> > Thus match will find foo at
> >
> > foobar
> >
> > but not in
> >
> > sofoo
> >
> > You usually need to use search() to find the pattern anywhere
> > within the string.
> >
> > Also look at the thread earlier this week on using listdir() and
> > the fileinput module.
>
> Hello again and thanks for the encouragement.
>
> I have been working on this problem again today and switched to the fileinput
> method. What I can't figure out now is how to pass a compiled regex to an
> optparse option. I'm confused ias to "option" versus "arg" when using the
> optparse module. In fact there seems to be no way to define what the arg
> should be; only options. Is the arg always implied? I have read several pages
> on optparse and am none the wiser.
>
> How do I fix the rx = re.compile('-x') line below so that the string I pass
> on the command line gets passed into the re.compile?
>
> #!/usr/bin/python
> import fileinput, sys, string, optparse, re
>
> #def main():
> optparser = optparse.OptionParser()
> optparser.add_option("-x", "--regx", help="regular expression")
> # take the first argument out of sys.argv and assign it to searchterm
> #searchterm, sys.argv[1:] = sys.argv[1], sys.argv[2:]
> (options, args) = optparser.parse_args()
Do you want to use optparse, or get the command line arguments yourself?
It seems the pattern string will be the first arg, will it?
> rx = re.compile('-x')
Then, if the note above is right, you have:
pat_string = sys.argv[1]
rx = re.compile(pat_string) # pattern object
Is that what you wish to do?
> for line in fileinput.input():
> num_matches = string.count(line, rx)
Above you are counting the number of *regex pattern* may be inside a
string. Not the number of (sub)strings matching the pattern, which is
probably what you intend.[ Also, you are using a deprecated function
"count" of the string module. Use line.count(substring) instead. Anyway,
this is probably not what you want.]
To count the number of pattern matches, you must use the
"matching" (lol) regex method, namely findall:
result_list = rx.findall(line)
> if num_matches:
> print "found '%s' %d times in %s on line %d." % (rx, num_matches,
> fileinput.filename(), fileinput.filelineno())
Do you want to print only the last match? If not, you need to record
matches found by the search loop into a list.
> #if __name__ == '__main__':
> #main()
_______________________________________________
Tutor maillist - [email protected]
http://mail.python.org/mailman/listinfo/tutor
