如果我们可以编写我们希望导入的类别层次结构，这不是很方便吗

apple|Apple|Apple products
 iphone-6s|Iphone 6s|Apple Iphone 6s
  iphone-6s-battery|Iphone 6s battery|Apple Iphone 6s battery
  iphone-8-battery|Iphone 8 battery|Apple Iphone 8 battery

每行为：

term slug|term name|term description

以及缩进定义的层次结构。

示例#1

使用空格进行缩进和| 作为列分隔符：

$import = \'
a1|A1|Term description
 a11|A11|Term description
  a111|A111|Term description
  a112|A112|Term description
 a12|A12|Term description
\';

wpse324129_bulk_terms_importer( $import, \'category\', \'|\', PHP_EOL );

这将导入以下条款：

示例#2

另一个使用制表符进行缩进和逗号作为列分隔符的示例：

$import = \'
a1,A1,"Term description, including column delimiter"
    a11,A11, "Term description, including column delimiter"
        a111,A111,"Term description, including column delimiter"
        a112,A112,"Term description, including column delimiter"
    a12,A12,"Term description, including column delimiter"
\';

wpse324129_bulk_terms_importer( $import, \'category\', \',\', PHP_EOL );

将术语导入为：

实现

这是这样一个从字符串批量导入术语的函数的初稿：

 /**
  * Bulk Term Importer
  *
  * Bulk import terms with a given hierarchy, defined by indentation (tab or space).
  *
  * @version 0.1.3
  *
  * @see https://wordpress.stackexchange.com/a/324157/26350
  *
  * @param string $import        Terms to import
  * @param string $tax           Taxonomy. Default \'category\'.
  * @param string $col_delimiter Column delimiter. Default \'|\'.
  * @param string $row_delimiter Row delimiter. Default PHP_EOL.
  */
function wpse324129_bulk_term_importer( $import, $tax = \'category\', $col_delimiter = \'|\', $row_delimiter = PHP_EOL ) {
    $rows         = explode( $row_delimiter, trim( $import ) );
    $level        = 0;
    $prev_term_id = 0;
    $ancestors    = new \\SplStack(); // Last-In First-Out.

    foreach( $rows as $row ) {
        $cols = str_getcsv( $row, $col_delimiter );
        if ( 3 !== count( $cols ) ) {
            throw new Exception( __( \'Incorrect number of columns\', \'wpse\' ) );
        }
        $term_slug = $cols[0];
        $term_name = $cols[1];
        $term_desc = $cols[2];

        // Hierarchy traversal level (non negative).
        $level = strlen( $term_slug ) - strlen( ltrim( $term_slug ) );

        // Push the previous term to the ancestors stack if we go inner (right).
        if ( $level > $ancestors->count() ) {
            $ancestors->push( $prev_term_id );
        } // After: level === ancestors count

        // Reduce the ancestors\' stack when we go outer (left).
        while ( $level < $ancestors->count() ) {
            $ancestors->pop();
        } // After: level === ancestors count

        // Arguments for term creation.
        $args = [
            \'description\' => $term_desc,
            \'slug\'        => $term_slug,
        ];

        // Check parent term and add to the term creation arguments if needed.
        if ( $prev_term_id > 0 && $ancestors->count() > 0 ) {
            $parent_id   = $ancestors->top(); // The parent is the one on the top.
            $parent_term = get_term_by( \'term_id\', $parent_id, $tax, ARRAY_A );
            if ( isset( $parent_term[\'term_id\'] ) ) {
                $args[\'parent\'] = $parent_term[\'term_id\'];
            }
        }

        // Check if current term slug exists and insert if needed.
        $term = get_term_by( \'slug\', $term_slug, $tax, ARRAY_A );   
        if ( ! isset( $term[\'term_id\'] ) ) {    
            $result = wp_insert_term( $term_name, $tax, $args );
            if ( is_wp_error( $result ) ) {
                throw new Exception( __( \'Could not insert term!\', \'wpse\' ) );
            }
            $prev_term_id = $result[\'term_id\'];
        } else {
            $prev_term_id = $term[\'term_id\'];
        }
    }
}

当我们插入一个术语时，我们需要知道它的父项。因此，我们需要在遍历层次结构时收集直接项祖先。这个stack 是一种合适的数据结构，其中最后一项是第一项（后进先出）。在PHP 5.3+中，我们可以使用SplStack 已经实现了如下方法pop(), push(), top() 和count().

通过将当前级别与当前祖先的数量进行比较，我们可以确定是内部（右）还是外部（左），并相应地调整堆栈。当我们向左移动时减少堆栈，当我们向右移动时推动堆栈。

对于大型导入，可以通过wp-cli 以避免超时。

希望您可以进一步扩展此功能以满足您的需要，例如使用格式验证器以及如何处理现有条款（我们目前不影响这些条款）。

测试前请备份！