perl - 多个文件句柄打开同一文件

我有grades.tsv文件，其中包含三列，分别显示学生的姓名，科目和成绩：

Liam    Mathematics 5
Liam    History 6
Liam    Geography   8
Liam    English 8
Aria    Mathematics 8
Aria    History 7
Aria    Geography   6
Isabella    Mathematics 9
Isabella    History 4
Isabella    Geography   7
Isabella    English 5
Isabella    Music   8

我想计算每个学生的平均成绩，并将其添加到单独的列中。为此，我使用了两个文件句柄DATA和OUT打开同一文件：

use strict;
use warnings;

# Open file with grades for calculation of average grade for each student
open (DATA,"grades.tsv") or die "Cannot open file\n";

my %grade_sums;
my %num_of_subjects;

# Calculate sum of grades and number of subjects for each student
while( <DATA> ) {

   chomp;
   my ($name, $subject, $grade) = split /\t/;

   $grade_sums{$name} += $grade;
   $num_of_subjects{$name} += 1;
}

close DATA;


# Open file with grades again but this time for a purpose of adding a separate column with average grade and printing a result
open (OUT,"grades.tsv") or die "Cannot open file\n";

while ( <OUT> ) {
   chomp;
   my ($name, $subject, $grade) = split /\t/;

   # Calculate average grade
   my $average_grade = $grade_sums{$name} / $num_of_subjects{$name};
   my $outline = join("\t", $name, $subject, $grade, $average_grade);

   # Print a file content with new column
   print "$outline\n";
}

close OUT;

该代码有效，但是我不确定这是否是完成此任务的正确方法。这是一个好习惯还是应该有更好的方法？