perl - 如何使用 Perl 仅解析文件的一部分？

Question

我是 Perl 的新手，但我听说它非常适合解析文件，所以我想试一试。

我有一个包含以下示例信息的文本文件:

High school is used in some
parts of the world, particularly in
Scotland, North America and Oceania to
describe an institution that provides
all or part of secondary education.
The term "high school" originated in
Scotland with the world's oldest being
the Royal High School (Edinburgh) in
1505.

The Royal High School was used as a
model for the first public high school
in the United States, the English High
School founded in Boston,
Massachusetts, in 1821. The precise
stage of schooling provided by a high
school differs from country to
country, and may vary within the same
jurisdiction. In all of New Zealand
and Malaysia along with parts of
Australia and Canada, high school is
synonymous with secondary school, and
encompasses the entire secondary stage
of education.

======================================
Grade1 87.43%
Grade2 84.30%
Grade3 83.00%
=====================================

我想解析文件，只获取数字信息。一世
查看正则表达式，我想我会使用类似的东西

if (m/^%/) {
    do something
}
else {
    skip the line
}

但是，我真正想做的是跟踪变量
left 并将数值存储在该变量中。所以，经过
解析文件，我真的很想拥有以下变量
将 % 值存储在其中。原因是，我想
创建不同等级的饼图/条形图。

Grade1 = 87.43 Grade2 = 84.30

...

你能建议我应该考虑的方法吗？

Answer 1

你需要一个正则表达式。像下面这样的东西应该工作

while (<>) {
  /(Grade[0-9]+)\s*([0-9]+\.[0-9]+)/;
  $op{$1} = $2;
}

作为过滤器。 op hash 将存储成绩名称和分数。这比自动实例化变量更可取。