function makeRange($length) {
    for ($i=0; $i<$length; $i++) {
        yield $i;
    }
}
foreach (makeRange(1000) as $i) {
    echo $i, PHP_EOL;
}

function getRows($file) {
    $handle = fopen($file, "rb");
    if ($handle === false) {
        throw new Exception();
    }
    while (feof($handle) === false) {
        yield fgetcsv($handle);
    }
    fclose($handle);
}

foreach (getRows('data.csv') as $row) {
    print_r($row);
}