WooCommerce - Adding product categories (one category per line), excerpt, and SKU to shop page

functions.php

/* Adding category, excerpt, and SKU to shop page */
add_action( 'woocommerce_after_shop_loop_item', 'prima_custom_shop_item', 5);
function prima_custom_shop_item() {
	global $post, $product;
	
	/* product categories */
	$size = sizeof( get_the_terms( $post->ID, 'product_cat' ) );
	echo $product->get_categories( '<br/>', '<p>', '</p>' );

	/* product excerpt */
	if ( $post->post_excerpt ) {
		echo apply_filters( 'woocommerce_short_description', $post->post_excerpt );
	}
	
	/* product sku */
	echo '<p>SKU: '.$product->get_sku().'</p>';
}

Tutorial: http://www.primathemes.com/documentation/adding-category-excerpt-and-sku-to-shop-page/