Read CSV file with embedded newlines

问题:

i'm working on a file i have scraped from a website, the file is saved as a semicolon csv with quoted fields. The last field contains embedded newlines. I've been working on a script to proces the file. I'm fairly new to perl and at first is was trying it with a normal perl script but quickly found out that wasn't working. I did my research and found out I should use the Text::CSV module instead. I came across these sites which explained how to use the module:

http://perlmaven.com/how-to-read-a-csv-file-using-perl

http://perlmeme.org/tutorials/parsing_csv.html

http://metacpan.org/pod/Text::CSV#Embedded-newlines

Basically what i'm trying to accomplish is to read the file correctly so that all the fields get delimited properly instead of breaking off at a newline. Then removing the newlines from that field and write it to a new file.

Here is an example of the original data:

 "2030";"NH Amersfoort";"Stationsstraat 75";"3811 MH AMERSFOORT";"033-4221200";"www.nh-hotels.nl";"52.154316";"5.380036";"<UL class=stars><LI>
 <LI>
 <LI>
 <LI></LI></UL>"
 "2031";"NH Amsterdam Centre";"Stadhouderskade 7";"1054 ES AMSTERDAM";"020-6851351";"www.nh-hotels.com";"52.363075";"4.879458";"<UL class=stars><LI>
 <LI>
 <LI>
 <LI></LI></UL>"
 "2032";"NH Atlanta Rotterdam Hotel";"Aert van Nesstraat 4";"3012 CA ROTTERDAM";"010-2067800";"www.nh-hotels.com";"51.921028";"4.478619";"<UL class=stars><LI>
 <LI>
 <LI>
 <LI></LI></UL>" 

And what i want is this:

 "2030";"NH Amersfoort";"Stationsstraat 75";"3811 MH AMERSFOORT";"033-4221200";"www.nh-hotels.nl";"52.154316";"5.380036";"<UL class=stars><LI><LI><LI><LI></LI></UL>"
 "2031";"NH Amsterdam Centre";"Stadhouderskade 7";"1054 ES AMSTERDAM";"020-6851351";"www.nh-hotels.com";"52.363075";"4.879458";"<UL class=stars><LI><LI><LI><LI></LI></UL>"
 "2032";"NH Atlanta Rotterdam Hotel";"Aert van Nesstraat 4";"3012 CA ROTTERDAM";"010-2067800";"www.nh-hotels.com";"51.921028";"4.478619";"<UL class=stars><LI><LI><LI><LI></LI></UL>" 

This is my full script so far. I have tried 10 different options and suggestions and they're all not working!

 use strict;
 use warnings;    
 use Text::CSV;

 my $inputfile  = shift || die "Give input and output names!\n";
 my $outputfile = shift || die "Give output name!\n";

 open my $infile,  '<', $inputfile   or die "Sourcefile in use / not found :$!\n";
 open my $outfile, '>', $outputfile  or die "Outputfile in use :$!\n";

    my $csv = Text::CSV->new ({
binary => 1,
sep_char => ';'
});

while (my $elements = $csv->getline( $infile )) {
        my $stars = $elements->[8];
        #$ster =~ s/[\r\n]//g
        print "$stars\n\n";
        }

 close $infile;
 close $outfile;

This prints the field with the newlines in it correctly but hasn't removed them off course. How do i do that? Using a regex to substitute the newlines is not working. And the next question is when I do figure out how to clean up that field.. How do i print the new file?

回答1:

I'm not sure what you are asking here, because it seems you already have your answers. However, this code does work:

use strict;
use warnings;
use Text::CSV;

my $csv = Text::CSV->new ({
    binary => 1,
    sep_char => ';',
    eol => $/,                # to make $csv->print use newlines
    always_quote => 1,        # to keep your numbers quoted
});

while (my $row = $csv->getline( *DATA )) {
    $row->[8] =~ s/[\r\n]+//g;
    $csv->print(*STDOUT, $row);
}

__DATA__
"2030";"NH Amersfoort";"Stationsstraat 75";"3811 MH AMERSFOORT";"033-4221200";"www.nh-hotels.nl";"52.154316";"5.380036";"<UL class=stars><LI>
<LI>
<LI>
<LI></LI></UL>"
"2031";"NH Amsterdam Centre";"Stadhouderskade 7";"1054 ES AMSTERDAM";"020-6851351";"www.nh-hotels.com";"52.363075";"4.879458";"<UL class=stars><LI>
<LI>
<LI>
<LI></LI></UL>"
"2032";"NH Atlanta Rotterdam Hotel";"Aert van Nesstraat 4";"3012 CA ROTTERDAM";"010-2067800";"www.nh-hotels.com";"51.921028";"4.478619";"<UL class=stars><LI>
<LI>
<LI>
<LI></LI></UL>"

Pointers:

Using the eol option with Text::CSV's print makes it do what you expect, which is to print newlines. I used STDOUT as the output handle, but you can use any file handle you want.

I don't know why you say substitution does "not work" for you, but I suspect that perhaps you did something like this:

my $foo = $row->[8];
$foo =~ s/[\r\n]//g;
print @$row;

This does not change the values in $row, just the copy in $foo.