Question

我有两个文件file1.txt和file2.txt

file1.txt内容：

line 1 file 1
line 2 file 1
line 3 file 1

file2.txt内容：

line 1 file 2
line 2 file 2
line 3 file 2

并拥有以下ruby代码：

nin_file = File.open "file1.txt"
dev_id_file = File.open "file2.txt"

nin_file.each do |nin_line|
        dev_id_file.each do |dev_line|
                nin_line.delete!("\r\n")
                puts "#{nin_line}  =>   #{dev_line}"
        end
end

nin_file.close
dev_id_file.close


(1..3).each do |e1|
        (1..5).each do |e2|
                puts "#{e1} => #{e2}"
        end
end

这是输出（为什么内部每个都不能处理文件，但适用于范围！）

line 1 file 1  =>   line 1 file 2
line 1 file 1  =>   line 2 file 2
line 1 file 1  =>   line 3 file 2
1 => 1
1 => 2
1 => 3
1 => 4
1 => 5
2 => 1
2 => 2
2 => 3
2 => 4
2 => 5
3 => 1
3 => 2
3 => 3
3 => 4
3 => 5

Answer 1

nin_file.each的第一次迭代后，dev_id_file的流为空：

dev_id_file.each do |dev_line|
  puts "1  =>   #{dev_line}"
end
dev_id_file.each do |dev_line|
  puts "2  =>   #{dev_line}"
end

输出：

1  =>   line 1 file 2
1  =>   line 2 file 2
1  =>   line 3 file 2

要让它每次都有效，你需要在数组上完成它：

nin_file = File.readlines"file1.txt"
dev_id_file = File.readlines "file2.txt"

nin_file.each do |nin_line|
  dev_id_file.each do |dev_line|
    nin_line.delete!("\r\n")
    puts "#{nin_line}  =>   #{dev_line}"
  end
end

输出：

line 1 file 1  =>   line 1 file 2
line 1 file 1  =>   line 2 file 2
line 1 file 1  =>   line 3 file 2
line 2 file 1  =>   line 1 file 2
line 2 file 1  =>   line 2 file 2
line 2 file 1  =>   line 3 file 2
line 3 file 1  =>   line 1 file 2
line 3 file 1  =>   line 2 file 2
line 3 file 1  =>   line 3 file 2

Answer 2

第一次迭代后完全读取

file2。这就是为什么你没有看到任何进一步的路线。

这应该可以提供您想要的输出。

nin_file = File.open "file1.txt"
dev_id_file = File.open "file2.txt"

nin_file.each do |nin_line|
        dev_id_file.rewind
        dev_id_file.each do |dev_line|
                nin_line.delete!("\r\n")
                puts "#{nin_line}  =>   #{dev_line}"
        end
end

每个文件都不允许嵌套

2 个答案: