How not to output content if missing value using shortcode

I’m creating a shortcode to promote affiliate products, and I’m using a simple shortcode template where I fill out the variables and returns the formatted HTML with the product information.

My questions is how do I modify the shortcode so when one of the shortcode attribute is missing or does’t require a value the “return” doesn’t output empty html code for that part of the missing value?

function create_buysingle_shortcode($atts) {

	$atts = shortcode_atts(
		array(
			'img' => 'product_image',
			'title' => 'product_title',
                        'affiliate' => 'product_link',
			'action' => 'product_action',
		),
		$atts,
		'buysingle'
	);

  $img = $atts['img'];
  $title = $atts['title'];
  $affiliate = $atts['affiliate'];
  $action = $atts['action'];
  $upload_dir = wp_get_upload_dir();
  $description = $atts['description'];

    return '<div id="item"><div id="product-recommendation-card"><div id="product-recommendation-photo"><img src="' . $upload_dir['baseurl'] . '/' . $img . '"></div><div class="product-info-wrapper"><div id="product-recommendation-text">' 
      . $title . 
      '</div><div id="product-recommendation-description">' . $description . '</div><div id="product-recommendation-button"><a href="' 
      . $affliate . 
      '">' 
      . $action . 
      '</a></div></div></div></div>';

}
add_shortcode( 'buysingle', 'create_buysingle_shortcode' );