#!/usr/bin/perl

 use Text::ParseWords;                                                
+   
use Data::Dumper;                                                     
+ 

                                                                      

use IO::File;                                                         

#my $file = test.csv;                                                 
+ 
my $file  = $ARGV[0];                                                 
my ($output_file) = ($file =~ /(.*)\./);                              
+ 
                                                            
open(my $fh, '<', $file) or die "Can't read csv file '$file' [$!]\n"; 
+ 

my $countlines = 0;   

my $countlines1 = 0;                                                  

while (my $line = <$fh>)
{while (my $line = <$fh>) 
{  chomp $line;
    my @fields = Text::ParseWords::parse_line(',', 0,$line);          
+ 
 if($countlines >= 0  && @fields[0]==201120)
{if ( @fields[1]==1){ $countlines1 = $countlines1 + 1;} 


$countlines++; 
    
}                                                     
                                                        
}

print "$countlines\n";
print "$countlines1\n"; 


$yield = ($countlines1 / $countlines)*100 ;

print $yield;                                 

 }
[download]

Thank for your reply,it does not have to be the same csv file. Currently , my code able read one week only and print it volume and yield. I need some guides from you all.

First, use Text::CSV_XS instead of Text::ParseWords - it reads more like the spec that way (having your code match your spec is always good in my books). Second, I don't see any commas in your original data, so there is an obvious mismatch.

Next, you are hardcoding your week number in your code. Don't do that. Accumulate it in a hash. I would even go so far as use a hash of hashes with separate fields for the sum and count.

Also, learn to use proper indentation. Your code is quite simply a mess. It's very difficult to follow nesting, and would get impossible to follow fairly quickly.

I also see a while inside a while, both reading from the same file. That's nonsensical. Instead, just read and discard a single line: scalar <$fh> should do it.

my %data;
my $csv = Text::CSV_XS->new();
scalar <$fh>;
while (my $row = $csv->getline($fh))
{
  $data{$row->[0]}{sum} += $row->[1];
  $data{$row->[0]}{count}++;
}

for my $weeknum (sort keys %data)
{
  printf "%s %d %.1f\n", $weeknum,
                         $data{$weeknum}{sum} / $data{$weeknum}{count}
+,
                         $data{$weeknum}{count};
}
[download]

That should give you enough to go on.

Update: s/comments/comma/ in the first paragraph

hi, sorry ya, i am newbie in perl

can i know what if i have a csv file like below?

 week    power   test     Test_end_date_time
201120   5        1       05-10-2011_16:47
201120   699      17      05-10-2011_16:48
201120   454      1       05-10-2011_16:49
201121   5687     26      12-10-2011_15:47
201121   211      1       12-10-2011_15:48
201121   1231     36      12-10-2011_15:49
201121   171      1       12-10-2011_15:50
201121   677      57      12-10-2011_15:51
201121   178      1       12-10-2011_15:52
 
if test = 1 mean pass, other than 1 is fail

I wish the output in another csv is like below, is it correct to use @
+field??

week   volume    yield
201120 3         66.7%
201121 6         50.0%
[download]