I have run into another problem in relation to a site I am trying to scrape.
Basically I have stripped most of what I don't want from the page content and thanks to some help given here have managed to isolate the dates I wanted. Most of it seems to be working fine, despite some initial problems matching a non-breaking space. However, I am now having difficulty with the final regex, which is intended to split each line of data into fields. Each line represents the price of a share price index. The fields on each line are:
A name of arbitrary length made from characters from the latin alphabet and sometimes a comma or ampersand, no numerics.
A number with two digits after the decimal point (the absolute value of the index).
A number with two digits after the decimal point (the change in the value).
A number with two digits after the decimal point followed by a percent sign (the percentage change in value).
Here is an example string, before splitting:
"Fishery, Agriculture & Forestry243.45-1.91-0.78% Mining360.74-4.15-1.14% Construction465.36-1.01-0.22% Foods783.2511.281.46% Textiles & Apparels412.070.540.13% Pulp & Paper333.31-0.29-0.09% Chemicals729.406.010.83% "
The regex I am using to split this line is this:
$mystr =~ s/\n(.*?)(\d{1,4}\.\d{2})(\-?\d{1,3}\.\d{2})(.*?%)\n/\n$1 == $2 == $3 == $4\n/ig;
It works sometimes but not other times and I cannot work out why this should be. (The doubled equal signs in the example output below are used to make the field split more easily visible.)
Fishery, Agriculture & Forestry == 243.45 == -1.91 == -0.78%
Mining360.74-4.15-1.14%
Construction == 465.36 == -1.01 == -0.22%
Foods783.2511.281.46%
I thought the minus sign was an issue for those indices that saw a negative change in the price of the index, but sometimes it works despite the minus sign.
Q. Why is the final regex shown below failing to split the fields consistently?
Example code follows.
#!/usr/bin/perl -w
use strict;
use LWP::Simple;
use HTML::Tree;
my $url_full = "http://www.tse.or.jp/english/market/STATISTICS/e06_past.html";
my $content = get($url_full);
# get dates:
(my #dates) = $content =~ /(?<=dateFormat\(')\d{4}\/\d{2}\/\d{2}(?='\))/g;
foreach my $date (#dates) { # convert to yyyy-mm-dd
$date =~ s/\//-/ig;
}
my $tree = HTML::Tree->new();
$tree->parse($content);
my $mystr = $tree->as_text;
$mystr =~ s/\xA0//gi; # remove non-breaking spaces
# remove first chunk of text:
$mystr =~
s/^(TSE.*?)IndustryIndexChange ?/IndustryIndexChange\n$dates[0]\n\n/gi;
$mystr =~ s/IndustryIndexChange ?/IndustryIndexChange/ig;
$mystr =~ s/IndustryIndexChange/Industry Index Change\n/ig;
$mystr =~ s/% /%\n/gi; # percent symbol is market for end of line
# indicate breaks between days:
$mystr =~ s/Stock.*?IndustryIndexChange/\nDAY DELIMITER\n/gi;
$mystr =~ s/Exemption from Liability.*$//g; # remove boilerplate at bottom
# and here's the problem regex...
# try to split it:
$mystr =~
s/\n(.*?)(\d{1,4}\.\d{2})(\-?\d{1,3}\.\d{2})(.*?%)\n/\n$1 == $2 == $3 == $4\n/ig;
print $mystr;
It appears to be doing every other one.
My guess is that your records have a single \n between them, but your pattern starts and ends with a \n. So the final \n on the first match consumes the \n that the second match needed to find the second record. The net result is that it picks up every other record.
You might be better off wrapping your pattern in ^ and $ (instead of \n and \n), and using the m flag on the s///.
The problem is that you have \n both at the start and at the end of the regex.
Consider something like this:
$s = 'abababa';
$s =~ s/aba/axa/g;
that will set $s to axabaxa, not axaxaxa, because there are only two non-overlapping occurrences of aba.
My interpretation (pseudocode) -
one = [a-zA-Z,& ]+
two = \d{1,4}.\d\d
three = <<two>>
four = <<two>>%
regex = (<<one>>)(<<two>>)(<<three>>)(<<four>>)
= ([a-zA-Z,& ]+)(\d{1,4}.\d\d)(\d{1,4}.\d\d)(\d{1,4}.\d\d%)
However, you are already presented with 'structured' data in the form of HTML. Why not take advantage of this?
HTML parsing in perl references MOJO
for DOM based parsing in perl, and unless there are serious performance reasons,
I'd highly recommend such an approach.
Related
I have a data file with the following.
Some random text here
1
2
3
13
Show:
120
items per page
I want to remove the numbers, "Show:" and the number below.
So the result becomes
Some random text here
items per page
I have the following code:
my $Showing = "((\\d{1,}\\n))*Show:\\n\\d{1,}\\n";
$FileContents =~ s/$Showing//ig;
which results in the following:
Some random text here
1
2
3
items per page
It only removes one number above "Show:", I have tried a number of variations of the $Showing variable. How can I get this to work.
I have another data file with the following:
Showing 1 - 46 of 46 products
20
50
per page
With the code, this code works.
my $Showing = 'Showing.*\n((\\d{1,}\\n)*)';
$FileContents =~ s/$Showing//ig;
The difference is the numbers are below "Showing", whereas for the one that does not work the numbers are above.
The attempted regex appears OK, even though I'd avoid the double quotes (and thus the need to then escape things!). Better yet, use qr operator to first build the regex pattern
my $re = qr/(?:[0-9]+\s*\n\s*)+Show:\s*\n\s*[0-9]+\s*\n/;
Then
$text =~ s/$re//;
results in the wanted two lines. The whole file is in the string $text.
I've sprinkled that pattern with possible spaces everywhere, but then since \s mostly includes all manner of new lines you can probably leave only the \s+
my $re = qr/(?:[0-9]+\s+)+Show:\s+[0-9]+\s+/;
(I left explicit \n's in the first pattern to avoid confusion.)
It is possible that something's "wrong" with new lines in your file, like having a carriage return and linefeed pair (instead of just a newline character). So if this isn't working try to tweak the \n in the pattern.
Options are to use [\n\r]+ (either or both of linefeed and carriage return), or \R (Unicode newline), or \v (vertical space). Or \s+, equivalent to [\h\v]. See the perlrecharclass link above.
I would solve this by just doing multiple regexes. For example
#!/usr/bin/env perl
use strict;
use warnings;
use v5.32;
while (my $line = <>) {
next if $line =~ m/\A\d+\s*\z/xms;
next if $line =~ m/\AShow:\s*\z/xms;
print $line;
}
In Shell it works like
$ ./remover.pl data.txt
Some random text here
items per page
So I'm trying to put all numbered domains into on element of a hash doing this:
### Domanis ###
my $dom = $name;
$dom =~ /(\w+\.\w+)$/; #this regex get the domain names only
my $temp = $1;
if ($temp =~ /(^d+\.\d+)/) { # this regex will take out the domains with number
my $foo = $1;
$foo = "OTHER";
$domain{$foo}++;
}
else {
$domain{$temp}++;
}
where $name will be something like:
something.something.72.154
something.something.72.155
something.something.72.173
something.something.72.175
something.something.73.194
something.something.73.205
something.something.73.214
something.something.abbnebraska.com
something.something.cableone.net
something.something.com.br
something.something.cox.net
something.something.googlebot.com
My code currently print this:
72.175
73.194
73.205
73.214
abbnebraska.com
cableone.net
com.br
cox.net
googlebot.com
lstn.net
but I want it to print like this:
abbnebraska.com
cableone.net
com.br
cox.net
googlebot.com
OTHER
lstn.net
where OTHER is all the numbered domains, so any ideas how?
You really shouldn't need to split the variable into two, e.g. this regex will match the case you want to trap:
/\d{1,3}\.\d{1,3}$/ -- returns true if the string ends with two 1-3 long digits separated by a dot
but I mean if you only need to separate those domains that are not numbered you could just check the last character in the domain whether it is a letter, because TLDs cannot contain numbers, so you would do something like
/\w$/ -- if returns true, it is not a numbered domain (providing you've stripped spaces and new lines)
But I suppose it is better to be more specific in the regex, which also better illustrates the logic you are looking for in your script, so I'd use the former regex.
And actually you could do something like this:
if (my ($domain) = $name =~ /\.(\w+.\w+)$/)
{
#the domain is assigned to the variable $domain
} else {
#it is a number domain
}
Take what it currently puts, and use the regex:
/\d+\.\d+/
if it matches this, then its a pair of numbers, so remove it.
This way you'll be able to keep any words with numbers in them.
Please, please indent your code correctly, and use whitespace to separate out various bits and pieces. It'll make your code so much easier to read.
Interestingly, you mentioned that you're getting the wrong output, but the section of the code you post has no print, printf, or say statement. It looks like you're attempting to count up the various domain names.
If these are the value of $name, there are several issues here:
if ($temp =~ /(^d+\.\d+)/) {
Matches nothing. This is saying that your string starts with one or more letter d followed by a period followed by one or more digits. The ^ anchors your regular expression to the beginning of the string.
I think, but not 100% sure, you want this:
if ( $temp =~ /\d\.\d/ ) {
This will find all cases where there are two digits with a period in between them. This is the sub-pattern to /\d+\.\d+/, so both regular expressions will match the same thing.
The
$dom =~ /(\w+\.\w+)$/;
Is matching anywhere in the entire string $dom where there are two letters, digits. or underscores with a decimal between them. Is that what you want?
I also believe this may indicate an error of some sort:
my $foo = $1;
$foo = "OTHER";
$domain{$foo} ++;
This is setting $foo to whatever $dom is matching, but then immediately resets $foo to OTHER, and increments $domain{OTHER}.
We need a sample of your initial data, and maybe the actual routine that prints your output.
I have a question I am hoping someone could help with...
I have a variable that contains the content from a webpage (scraped using WWW::Mechanize).
The variable contains data such as these:
$var = "ewrfs sdfdsf cat_dog,horse,rabbit,chicken-pig"
$var = "fdsf iiukui aawwe dffg elephant,MOUSE_RAT,spider,lion-tiger hdsfds jdlkf sdf"
$var = "dsadp poids pewqwe ANTELOPE-GIRAFFE,frOG,fish,crab,kangaROO-KOALA sdfdsf hkew"
The only bits I am interested in from the above examples are:
#array = ("cat_dog","horse","rabbit","chicken-pig")
#array = ("elephant","MOUSE_RAT","spider","lion-tiger")
#array = ("ANTELOPE-GIRAFFE","frOG","fish","crab","kangaROO-KOALA")
The problem I am having:
I am trying to extract only the comma-separated strings from the variables and then store these in an array for use later on.
But what is the best way to make sure that I get the strings at the start (ie cat_dog) and end (ie chicken-pig) of the comma-separated list of animals as they are not prefixed/suffixed with a comma.
Also, as the variables will contain webpage content, it is inevitable that there may also be instances where a commas is immediately succeeded by a space and then another word, as that is the correct method of using commas in paragraphs and sentences...
For example:
Saturn was long thought to be the only ringed planet, however, this is now known not to be the case.
^ ^
| |
note the spaces here and here
I am not interested in any cases where the comma is followed by a space (as shown above).
I am only interested in cases where the comma DOES NOT have a space after it (ie cat_dog,horse,rabbit,chicken-pig)
I have a tried a number of ways of doing this but cannot work out the best way to go about constructing the regular expression.
How about
[^,\s]+(,[^,\s]+)+
which will match one or more characters that are not a space or comma [^,\s]+ followed by a comma and one or more characters that are not a space or comma, one or more times.
Further to comments
To match more than one sequence add the g modifier for global matching.
The following splits each match $& on a , and pushes the results to #matches.
my $str = "sdfds cat_dog,horse,rabbit,chicken-pig then some more pig,duck,goose";
my #matches;
while ($str =~ /[^,\s]+(,[^,\s]+)+/g) {
push(#matches, split(/,/, $&));
}
print join("\n",#matches),"\n";
Though you can probably construct a single regex, a combination of regexs, splits, grep and map looks decently
my #array = map { split /,/ } grep { !/^,/ && !/,$/ && /,/ } split
Going from right to left:
Split the line on spaces (split)
Leave only elements having no comma at the either end but having one inside (grep)
Split each such element into parts (map and split)
That way you can easily change the parts e.g. to eliminate two consecutive commas add && !/,,/ inside grep.
I hope this is clear and suits your needs:
#!/usr/bin/perl
use warnings;
use strict;
my #strs = ("ewrfs sdfdsf cat_dog,horse,rabbit,chicken-pig",
"fdsf iiukui aawwe dffg elephant,MOUSE_RAT,spider,lion-tiger hdsfds jdlkf sdf",
"dsadp poids pewqwe ANTELOPE-GIRAFFE,frOG,fish,crab,kangaROO-KOALA sdfdsf hkew",
"Saturn was long thought to be the only ringed planet, however, this is now known not to be the case.",
"Another sentence, although having commas, should not confuse the regex with this: a,b,c,d");
my $regex = qr/
\s #From your examples, it seems as if every
#comma separated list is preceded by a space.
(
(?:
[^,\s]+ #Now, not a comma or a space for the
#terms of the list
, #followed by a comma
)+
[^,\s]+ #followed by one last term of the list
)
/x;
my #matches = map {
$_ =~ /$regex/;
if ($1) {
my $comma_sep_list = $1;
[split ',', $comma_sep_list];
}
else {
[]
}
} #strs;
$var =~ tr/ //s;
while ($var =~ /(?<!, )\b[^, ]+(?=,\S)|(?<=,)[^, ]+(?=,)|(?<=\S,)[^, ]+\b(?! ,)/g) {
push (#arr, $&);
}
the regular expression matches three cases :
(?<!, )\b[^, ]+(?=,\S) : matches cat_dog
(?<=,)[^, ]+(?=,) : matches horse & rabbit
(?<=\S,)[^, ]+\b(?! ,) : matches chicken-pig
I have following text pattern
(2222) First Last (ab-cd/ABC1), <first.last#site.domain.com> 1224: efadsfadsfdsf
(3333) First Last (abcd/ABC12), <first.last#site.domain.com> 1234, 4657: efadsfadsfdsf
I want the number 1224 or 1234, 4657 from the above text after the text >.
I have this
\((\d+)\)\s\w*\s\w*\s\(\w*\/\w+\d*\),\s<\w*\.\w*\#\w*\.domain.com>\s\d+:
which will take the text before : But i want the one after email till :
Is there any easy regular expression to do this? or should I use split and do this
Thanks
Edit: The whole text is returned by a command line tool.
(3333) First Last (abcd/ABC12), <first.last#site.domain.com> 1234, 4657: efadsfadsfdsf
(3333) - Unique ID
First Last - First and last names
<first.last#site.domain.com> - Email address in format FirstName.LastName#sub.domain.com
1234, 4567 - database primary Keys
: xxxx - Headline
What I have to do is process the above and get hte database ID (in ex: 1234, 4567 2 separate ID's) and query the tables
The above is the output (like this I will get many entries) from the tool which I am calling via my Perl script.
My idea was to use a regular expression to get the database id's. Guess I could use regular expression for this
you can fudge the stuff you don't care about to make the expression easier, say just 'glob' the parts between the parentheticals (and the email delimiters) using non-greedy quantifiers:
/(\d+)\).*?\(.*?\),\s*<.*?>\s*(\d+(?:,\s*\d+)*):/ (not tested!)
there's only two captured groups, the (1234), and the (1234, 4657), the second one which I can only assume from your pattern to mean: "a digit string, followed by zero or more comma separated digit strings".
Well, a simple fix is to just allow all the possible characters in a character class. Which is to say change \d to [\d, ] to allow digits, commas and space.
Your regex as it is, though, does not match the first sample line, because it has a dash - in it (ab-cd/ABC1 does not match \w*\/\w+\d*\). Also, it is not a good idea to rely too heavily on the * quantifier, because it does match the empty string (it matches zero or more times), and should only be used for things which are truly optional. Use + otherwise, which matches (1 or more times).
You have a rather strict regex, and with slight variations in your data like this, it will fail. Only you know what your data looks like, and if you actually do need a strict regex. However, if your data is somewhat consistent, you can use a loose regex simply based on the email part:
sub extract_nums {
my $string = shift;
if ($string =~ /<[^>]*> *([\d, ]+):/) {
return $1 =~ /\d+/g; # return the extracted digits in a list
# return $1; # just return the string as-is
} else { return undef }
}
This assumes, of course, that you cannot have <> tags in front of the email part of the line. It will capture any digits, commas and spaces found between a <> tag and a colon, and then return a list of any digits found in the match. You can also just return the string, as shown in the commented line.
There would appear to be something missing from your examples. Is this what they're supposed to look like, with email?
(1234) First Last (ab-cd/ABC1), <foo.bar#domain.com> 1224: efadsfadsfdsf
(1234) First Last (abcd/ABC12), <foo.bar#domain.com> 1234, 4657: efadsfadsfdsf
If so, this should work:
\((\d+)\)\s\w*\s\w*\s\(\w*\/\w+\d*\),\s<\w*\.\w*\#\w*\.domain\.com>\s\d+(?:,\s(\d+))?:
$string =~ /.*>\s*(.+):.+/;
$numbers = $1;
That's it.
Tested.
With number catching:
$string =~ /.*>\s*(?([0-9]|,)+):.+/;
$numbers = $1;
Not tested but you get the idea.
I am using the following perl regex lines
$myalbum =~ s/[-_'&’]/ /g;
$myalbum =~ s/[,’.]//g;
$myalbum =~ m/([A-Z0-9\$]+) +([A-Z0-9\$]+) +([A-Z0-9\$]+) +([A-Z0-9\$]+) +([A-Z0-9\$]+)/i;
to match the following strings
"30_Seconds_To_Mars_-_30_Seconds_To_Mars"
"30_Seconds_To_Mars_-_A_Beautiful_Lie"
"311_-_311"
"311_-_From_Chaos"
"311_-_Grassroots"
"311_-_Sound_System"
What I am experiencing is that for strings with less than 5 matching groups (ex. 311_-_311), attempting to print $1 $2 $3 prints nothing at all. Only strings with more than 5 matches will print.
How do I resolve this?
It looks like you just want the words in separate groups. To me, it seems like you're abusing regexes to do that when you could just run your substitutions and then split. Just do:
$myalbum =~ s/[-_'&’]/ /g;
$myalbum =~ s/[,’.]//g;
my #myalbum_list = split(/\s/, $myalbum);
#Print out whatever it is you want/ test length, etc...
print "$myalbum_list[0] $myalbum_list[1] $myalbum_list[2]";
the + character means at least one match. Which means your regex m/([A-Z0-9\$]+) +([A-Z0-9\$]+) + ... requires all those fields to be there for it to be considered a match. The reason you are not capturing anything is because it's not actually matching.
You are probably looking for the * character which means zero or more not one or more like +.
I suppose your capturing groups are empty for "311 - 311" because this string doesn't match your regex.
How to resolve? Use * instead of + to permit empty sequences.
Edit: From your post I guess you want to extract the album name, i.e. the part before the minus sign.
Why not match against '(.*) - (.*)', being the first group the album and the second the title. The problem is with strings like "Album with minus - sign - First track" or "My Album - Track is one - two - three". But also as a human you wouldn't know there where the album ends and the track starts.