perl - Perl如何仅对有两个单词的变量应用正则表达式？

Question

我想在我只有 2 个单词的行上应用正则表达式。我的文件看起来像这样，括号中的单词之间有可变数量的空格：

我想有一个输出：

我的代码在每一行上应用正则表达式，我得到如下错误输出：

这是我的代码：

use strict;
use warnings;
use Data::Dumper;
use utf8;

open(IN, $ARGV[0]) or die "Can't read file $ARGV[0]\n";
while (my $line=<IN>)
{
    my ($pol,$value) = split(/:/, $line);

    warn Dumper \$pol;
    chomp($value);
    $value=~ s/[  ]+/ /g;
    $value=~ s/\);//g;
    my $n;  
    $n = $1 if ($value =~ /\((.+?)\|/); 
    $n=~ m/(\w*)\s(\w*)/g;
    my $swapname="$2 $1";
    warn Dumper \$swapname;

    print "$pol: $value | $swapname );\n";

}
close(IN);

我需要做什么来停止处理三字名称？

score 2 · Accepted Answer

$n=~ m/(\w*)\s(\w*)/g;   # Replace this regex with the one below

使用下面的正则表达式进行比较，$n您还需要将其包含在中if，否则您的打印将为每个输入执行：-

my $n;  
$n = $1 if ($value =~ /\((.+?)\|/); 
if ($n =~ m/^\s*(\w+)\s(\w+)\s*$/g) {  # Notice `$` to mark the end of 2 words..
    my $swapname="$2 $1";
    warn Dumper \$swapname;

    print "$pol: $value | $swapname );\n";
}

但是，你没有考虑|..之后的下一个值。你需要这样做..它只是考虑第一个值..

所以，你的输出将是： -

Politician_name: (Tony Blair |tony blair | Tony Blair | tony blair | Blair Tony )

2ndtony blair不习惯。您需要为此修改代码。

实际上，您需要一个循环来遍历每个名称，以使此代码正常工作。

更新：-我宁愿将您的代码更改为：-

# You should always use lexical variables as file handles..
open my $fh, '<', 'D:\demo.txt' or die $!;

while (<$fh>)  # Don't need use any extra variable here.. Default to $_
{
    my ($pol,$value) = split /:/;  # Do split on $_ by default
    warn Dumper \$pol;

    chomp($value);

    $value=~ s/[  ]+/ /g;
    $value=~ s/\((.*)\);/$1/g;

    my @name = split(/\|/, $value);  # Split your string to an array

    # Filter out array to remove duplicate

    my $_ = $name[0]; 

    if (m/^\s*(\w+)\s(\w+)\s*$/g) {  

        # If first element contains 2 words, proceed with rest of the elements

        print "($value ";  # print the original string you want..

        # Append to it later on the reverse of other array elements

        foreach (@name) {
            if (m/^\s*(\w+)\s(\w+)\s*$/g) {

                my $swapname = "$2 $1";
                warn Dumper \$swapname;

                print "| $swapname ";  # Print swapnames after $value
            }
        }
        print ");\n";  # End the string..
    }
}
close($fh);

perl - Perl如何仅对有两个单词的变量应用正则表达式？

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