Tips：

1.代码中的注释行应该单独一行，前后各空一行，以免造成代码高亮显示错误；

2.在代码中已经添加代码高亮后，代码需要空行时可用 shift+enter键添加空行，而直接enter代码块会断裂；

如下是空行后，完美显示：

use Bio::SeqIO;
use Bio::Seq;
use Data::Dumper;
$in  = Bio::SeqIO->new(-file => "D:/share/scripts/Arabidopsis_thaliana.TAIR10.cds.all.fa" ,
                               -alphabet=>"dna",
                               -format => 'Fasta');
$out = Bio::SeqIO->new(-file => ">D:/share/scripts/aa.fa" ,
                               -format => 'fasta');
while ( my $seqobj = $in->next_seq() ) {

# the human read-able id of the sequence

my $id=$seqobj->id(); 
 
# string of sequence

my $seq=$seqobj->seq();

# a description of the sequence

my $desc=$seqobj->desc(); 

# one of 'dna','rna','protein'  https://www.bioinformatics.org/sms/iupac.html

my $alphabet=$seqobj->alphabet(); 
my $len=$seqobj->length();
print $id."\n";
print $seq."\n";
print $desc."\n";
print $alphabet."\n";
print $len."\n";
print $seqobj."\n";
print Dumper($seqobj);
$out->write_seq($seqobj);
last;
}

如果没有空行，代码显示会有错误：

use Bio::SeqIO;
use Bio::Seq;
use Data::Dumper;
$in  = Bio::SeqIO->new(-file => "D:/share/scripts/Arabidopsis_thaliana.TAIR10.cds.all.fa" ,
                               -alphabet=>"dna",
                               -format => 'Fasta');
$out = Bio::SeqIO->new(-file => ">D:/share/scripts/aa.fa" ,
                               -format => 'fasta');
while ( my $seqobj = $in->next_seq() ) {
# the human read-able id of the sequence
my $id=$seqobj->id(); 
 
# string of sequence
my $seq=$seqobj->seq();
# a description of the sequence
my $desc=$seqobj->desc(); 
# one of 'dna','rna','protein'  https://www.bioinformatics.org/sms/iupac.html
my $alphabet=$seqobj->alphabet(); 
my $len=$seqobj->length();
print $id."\n";
print $seq."\n";
print $desc."\n";
print $alphabet."\n";
print $len."\n";
print $seqobj."\n";
print Dumper($seqobj);
$out->write_seq($seqobj);
last;
}