rclpy import error tutorial

edit

In /robot_operating_system/ros2/tutorials/tutorial_2

I tried to run

ros2 run demo_nodes_py talker

and the output is as follows

ModuleNotFoundError: No module named 'rclpy._rclpy'

Can anyone help me?

I also just can't run 'talker' as a command in the terminal.

Using ubuntu 18.04

Edit: I do have rclpy downloaded. Can anyone confirm if my env variables are wrong?

ROS_ETC_DIR=/opt/ros/melodic/etc/ros

ROS_ROOT=/opt/ros/melodic/share/ros

ROS_MASTER_URI=http://localhost:11311

ROS_VERSION=2

ROS_PYTHON_VERSION=3

ROS_PACKAGE_PATH=/home/dominick/ros2_install/ros2-linux/share

ROSLISP_PACKAGE_DIRECTORIES=

ROS_DISTRO=bouncy