php如何从csv文件转换数据？

我有一个csv文件，其中包含如下数据

shelfmark, centuries
foo-0001, 2000s;
bar-1234, 1200s, 1300s;
baz-IK-1234, 0100s, 0200s, 0300s;
and so on...

我想导入数据并将其转换为只有两列的格式：

shelfmark, century
foo-0001, 2000s;
bar-1234, 1200s;
bar-1234, 1300s;
baz-IK-1234, 0100s;
baz-IK-1234, 0200s;
baz-IK-1234, 0300s;
and so on...

并将其写入新的csv文件中

如果一行包含超过一个世纪的值，我需要有关创建新行的代码的帮助

我的尝试：

<?php
    $csv = array_map('str_getcsv', file($file));
    array_walk($csv, function(&$a) use ($csv) {
      // check if row has more than two column entries
      if
      // if so then split the first century value into a new row 
      // do so until no more century value is in the row left and continue with next row
      $data = array_combine($csv[0], $a);
    });
    // write into new csv file
    $fp = fopen('php://output', 'w');
    foreach ( $data as $line ) {
        $val = explode(",", $line);
        fputcsv($fp, $val);
    }
    fclose($fp);

?> 

---

您可以通过使用

array\u shift（）

在最终内容上循环，只需去掉行标题（'foo-0001'），然后将其添加到数组中的每个剩余元素，从而简化流程

这使用

fwrite（）

来维护内容格式

$csv = array_map('str_getcsv', file($file));
// Take the titles out of the main list of lines
$titles = array_shift($csv);
$fp = fopen('php://output', 'w');
// Add the header row
fwrite($fp, implode(",", $titles).PHP_EOL);
foreach ( $csv as $line ) {
    $header = array_shift($line);   // Remove the first part from the array
    foreach ( $line as $entry )  {
        fwrite($fp, $header.",". trim($entry,";").";".PHP_EOL);
    }
}
fclose($fp);