WooCommerce - Exclude products from a particular category on the shop page

functions.php

add_action( 'pre_get_posts', 'custom_pre_get_posts_query' );

function custom_pre_get_posts_query( $q ) {

	if ( ! $q->is_main_query() ) return;
	if ( ! $q->is_post_type_archive() ) return;
	
	if ( ! is_admin() && is_shop() ) {

		$q->set( 'tax_query', array(array(
			'taxonomy' => 'product_cat',
			'field' => 'slug',
			'terms' => array( 'knives' ), // Don't display products in the knives category on the shop page
			'operator' => 'NOT IN'
		)));
	
	}

	remove_action( 'pre_get_posts', 'custom_pre_get_posts_query' );

}