ROSSKILL"[rospack] Error: package 'rosserial_python' not found"

[1348686364]

Hi,Vincrossers
I encountered some problems when testing ROSSkill. When I follow readme and ROS.org in a tutorial using rosserial (steps as follows):

1. Startd a terminal and executed:
   $ roscore
   

   

2. Then, executing in a new terminal:
   $ rosrun rosserial_python serial_node.py tcp
   However, the following error has occurred:
   [rospack] Error: package 'rosserial_python' not found"
   

   
   
   I also tried to enter the folder with rosserial_python operation, but the error is still the same.
   Folder Contents:
   

My system is Ubuntu 14.04 trusty, ROS version is indigo, rosserial installation is also done in accordance with the steps of this site as catkin, and no error.