php foreach wrap every 2 divs

Answer 1

You should open and close your <rows/> in the books loop, and add a late check for odd books:

<?php 
$count = 0;
foreach ($contents as $content) 
{
    //var_dump($content);
    $books      = $content["tags"];
    $book_image = $content['content_image'];
    $book_desc  = $content['content_social_description'];


    foreach ($books as $book) 
    {
        ++$count;
        if($count == 1)
        {  
            echo "<div class='et_pb_row'>";
        }
        $book_name      = $book['tag_name'];
        $book_name_trim = str_replace(' ', '-', $book_name);
        ?>
        <!-- Inside the Book Loop -->
        <div class='et_pb_column et_pb_column_1_2 books' style="background: url('https://s3-us-west-2.amazonaws.com/crowdhubproverbs31/<?php echo $book_image ;?>');">
            <h2><?php echo $book_name; ?></h2>
            <p><?php echo $book_desc; ?></p>
            <?php echo $count; ?>
        </div>

        <?php
        if ($count == 2)
        {
            echo "</div>";
            $count = 0;
        }


    }
}

if ($count > 0)
{
    echo "</div>";
}
?>

Doing so, your $count variable will be incremented only when foreach($books AS $book) loop is run (thus you have at least one book to print)

Answer 2

You can take advantage of array_chunk :

//First make a generator to get all books
function allBooks($contents) {
    foreach($contents as $content) {    
        foreach($content['tags'] as $book) {
            yield $book; //Here you can yield whatever you want !
        }
    }
}

//Then create rows
$itemPerRow = 2;
$rows = array_chunk(iterator_to_array(allBooks($contents)), $itemPerRow, true);

//Display all 
foreach($rows as $row) {
   echo '<row>';
      foreach($row as $book) {
         //Display the book !
      }
   echo '</row>';
}