Flysystem/CSV过滤列的子集 [英] Flysystem/CSV filter a subset of columns

问题描述

是否可以使用 Flysystem CSV 过滤CSV列的子集?

Is it possible to filter a subset of columns of a CSV with Flysystem CSV?

我知道您可以使用AbstractCsv::addFilter(callable $callback)添加任意过滤器，但是我认为您不会使用它来删除列.

I know that you can use AbstractCsv::addFilter(callable $callback) to add arbitrary filters, but I don't think you would use this to drop a column.

推荐答案

我通过获取要过滤掉的列位置数组解决了这一问题.然后，通过设置一个新的CSV对象来写入例如

I solved this by getting an array of the column positions that I wanted to filter out. Then, by setting up a new CSV object to write to e.g.

$new = Writer::createFromFileObject(new \SplTempFileObject);

要读取CSV，我使用了each方法来遍历其行，使用先前构建的列索引来构建新行，然后插入到新CSV中.记住要使用each方法中的return true;，否则它不会迭代.

With the CSV to read from, I used the each method to iterate through its rows, building a new row using the column indexes built earlier on and inserting into the new CSV. Remember to return true; in the each method or it won't iterate.

$csv = $csv->newReader();
$csv->setOffset(1);
$csv->each(function ($row) use ($new) {
    ... do stuff to alter the row ...
    $new->insertOne($alteredRow)
});

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