List Contributors

// WP_User_Query arguments
$args = array(
	'role'           => 'Contributor',
);

// The User Query
$users = new WP_User_Query( $args );

// The User Loop
if ( ! empty( $users->results ) ) {
	foreach ( $users->results as $user ) {
		// do something
	}
} else {
	// no users found
}