Question

我是Perl的初学者，目前正致力于使用Perl脚本来自动化我们的一些任务。我正在处理的一个脚本涉及从我们的系统中提取性能数据，将其存储在CSV文件中并生成Excel图形。在处理完这个脚本几天之后，我设法将提取的数据转换成CSV，但是现在，我很难设法转换数据！我已经看过这个帖子（感谢dalton的脚本）：stackoverflow thread，但我似乎无法应用它。

基本上，我的CSV文件包含每行的每日数据，列数为一天中的小时数（24小时）：

29-Aug-2013,3.68,3.63,3.75,3.65,3.65,3.11,3.34,2.74,2.83,2.52,3.19,4.24,3.84,3.61,3.69,2.96,2.76,2.91,3.70,3.82,3.70,3.54,2.54,3.90
30-Aug-2013,3.46,2.97,3.83,3.55,3.41,3.47,3.32,2.81,2.80,2.32,3.17,3.60,3.63,3.83,3.67,2.92,2.34,3.21,3.45,3.51,3.57,3.46,3.52,4.19
31-Aug-2013,3.19,3.50,4.01,3.91,3.71,3.33,3.20,2.95,2.90,2.37,3.07,3.48,2.86,3.29,3.22,2.52,1.83,2.83,3.54,3.49,3.62,3.59,3.54,3.31
01-Sep-2013,2.88,3.16,2.79,2.90,3.78,3.18,3.26,2.84,3.21,2.50,3.35,3.78,3.30,4.04,3.80,3.07,3.23,3.54,3.30,3.43,3.56,3.48,3.60,3.78
02-Sep-2013,3.28,2.92,3.89,3.78,3.54,3.09,3.08,2.79,2.87,2.43,2.70,3.64,3.79,3.88,3.88,3.28,2.90,3.37,3.25,3.60,3.45,3.39,2.84,4.07
03-Sep-2013,3.31,2.54,3.59,3.59,3.50,3.10,2.98,2.63,3.20,2.53,2.92,3.42,3.76,3.07,3.41,2.42,2.12,3.19,3.32,3.08,3.63,3.50,3.71,3.75
04-Sep-2013,3.64,3.48,2.86,3.57,3.68,3.53,3.34,2.89,2.79,2.64,3.30,4.04,4.17,3.70,3.81,2.96,3.41,3.48,3.66,3.05,3.23,3.41,3.15,4.31

现在，我想转置它，以便我将写入新CSV文件的结果数据如下所示：

Time,29-Aug-2013,30-Aug-2013,1-Sep-2013,2-Sep-2013,3-Sep-2013,4-Sep-2013
01:00,3.68,3.46,3.19,2.88,3.28,3.31,3.64
02:00,3.63,2.97,3.50,3.16,2.92,2.54,3.48
03:00,3.75,3.83,4.01,2.79,3.89,3.59,2.86
...

现在，我的脚本看起来像这样：

my @rows = ();
my @transposed = ();

open F1,"D:\\Temp\\perf_data.csv";
while(<F1>) {
    chomp;
    push @rows, split [ /,/ ];
}
#print @rows;

for my $row (@rows) {
  for my $column (0 .. $#{$row}) {
    push(@{$transposed[$column]}, $row->[$column]);
  }
}

for my $new_row (@transposed) {
  for my $new_col (@{$new_row}) {
      print $new_col, ",";
  }
  print "\n";
}

我甚至无法从中获得结果！有人可以帮我提一下如何做到这一点吗？提前谢谢！

Answer 1

你犯了一个简单而又严重的错误。

split [ /,/ ]

应该是

[ split /,/ ]

split的语法是

split /PATTERN/, EXPR, LIMIT

后两者是可选的。你正在做的是将匿名数组引用为PATTERN，这很可能会被字符串化为类似ARRAY(0x54d658)的内容。结果是该线未被分割，并且整条线被推到阵列上。稍后，这将导致$row的取消引用失败并显示错误

Can't use string ("29-Aug-2013,3.68,3.63,3.75,3.65,"...) as an ARRAY ref while "
strict refs" in use at foo.pl line 18, <F1> line 7.

Answer 2

这是我的Perl程序，用于将行数据转置为列。一行以标题名称开头，后跟一个或多个值。就我而言，我需要从标题中删除日期（mm / dd / yyyy），以便标题字段的其余部分在多行中是唯一的。

sub usage { << "EOF";

Convert rows to columns.
Remove dates from column headings. 

Usage:
    perl $0
Example:
   $0 data-to-transpose.txt

Source data:
    header1, row1Value1, row2Value2
    header2, row2Value1
    header3 11/31/2011, row3Value1, row3Value2
Output:
    header1, header2, header3
    row1Value1, row2Value1, row3Value1
    row1Value2, , row3Value2

EOF
}
#
#-------------------------------------------------------------------------------

use 5.010;
use strict;
use warnings;

# use Data::Dumper;
sub printColumns;

my $inFile = shift or die usage();
# @ARGV = ('.') unless @ARGV;

my @headers;        # Order list of column headers
my %data;           # map{colHeader, arrayColSourceData }
my $colCnt = 0;     # maximum number of columns in source data, header, value1, value2, ....
my $printColHeaders = 1;

my %hasharray; open (my $fh, "<", $inFile) or die "can't open the $inFile";
while (<$fh>) {
    chomp;
    my @parts = split /,/; 

    if (@parts > 1) {
        # Remove date from heading field
        (my $header = $parts[0]) =~ s/[0-9]+\/[0-9]+\/[0-9]+//;

        if (!exists $data{$header}) {
           push @headers, $header;
        }

        my $have = $data{$header};
        if (defined $data{$header}) {
            if ($printColHeaders == 1) {
                $printColHeaders = 0;
                foreach my $col (@headers) {
                    print "$col,";
                }
                print "\n";
            }

            printColumns();

            foreach my $col (@headers) {
                 $data{$col} = undef;
            }
        } 

        $data{$header} = \@parts;
        $colCnt = (@parts > $colCnt) ? @parts : $colCnt;
    }
} 

printColumns();
print "\n";

foreach my $col (@headers) {
    print "$col,";
}
print "\n";

#### Subs 
sub printColumns() {
    for my $row (1 .. $colCnt-1) {
        foreach my $colHeader (@headers) {
            my $colData = $data{$colHeader};
            if (defined $colData) {
                my $len=@$colData;
                if (defined $colData && $row < @$colData) {
                    print "$colData->[$row], ";
                } else {
                    print ", ";
                }
            } else {
                print ", ";
            }
        }
        print "\n";
    } 
}

在Perl中转置CSV数据

2 个答案: