Hide products by category from the shop page

wcs_hide_unwanted_category.php

<?php

/**
 * Exclude products from a particular category on the shop page
 */
function wcs_hide_unwanted_category( $q ) {
	$tax_query = (array) $q->get( 'tax_query' );
	$tax_query[] = array(
		'taxonomy' => 'product_cat',
		'field' => 'slug',
		'terms' => array( 'not-displayed' ), // Don't display products in the clothing category on the shop page.
		'operator' => 'NOT IN'
		);
		$q->set( 'tax_query', $tax_query );
}
add_action( 'woocommerce_product_query', 'wcs_hide_unwanted_category' );