Using wp_insert_post to create posts in bulk via CSV import

smart_seo_import_update.php

<?php 
add_action( 'smart_seo_import_update', '_child_theme_create_post_with_custom_fields', 10, 3 );
function _child_theme_create_post_with_custom_fields($post_id, $data, $columns){

    if( $post_id == 0 || $post_id == '0' ){

        $args = array(  'post_title' => $data['post_title'], 
                        'post_status' => 'publish',
                        'post_type' => $data['post_type'] );

        // only create post if no same post is created
        $slug = sanitize_title( $data['post_title'] );
        $found = get_page_by_path( $slug, OBJECT, $data['post_type'] );

        if( is_null( $found ) ){

            $id = wp_insert_post( $args, false, false );

            if( $id ){

                $coords = explode(",", $data['coordinates'] );

                update_post_meta( $id, '_address', sanitize_text_field( $data['_address'] ) );
                update_post_meta( $id, '_suburb', sanitize_text_field( $data['_suburb'] ) );
                update_post_meta( $id, '_developer', sanitize_text_field( $data['_developer'] ) );
                update_post_meta( $id, '_contact_name', sanitize_text_field( $data['_contact_name'] ) );
                update_post_meta( $id, '_contact_no', sanitize_text_field( $data['_contact_no'] ) );
                update_post_meta( $id, '_external_link', sanitize_text_field( $data['_external_link'] ) );
                // update_post_meta( $id, '_latitude', $coords[0] );
                // update_post_meta( $id, '_longitude', $coords[1] );
                update_post_meta( $id, '_latitude', sanitize_text_field( $data['_latitude'] ) );
                update_post_meta( $id, '_longitude', sanitize_text_field( $data['_longitude'] ) );

            }
        }

    }
}

?>