Install robot framework with python in Ubuntu

I have tried installing Robot Framework with python in ubuntu. Firstly I installed Python and then I installed pip after that I installed Robot Framework

pip install robotframework

and then selenium library

pip install robotframework-selenium2library

with pip.

After that when I tried to install RIDE IDE using pip

pip install robotframework-ride

I am unable to install RIDE and I am getting an error like

Could not install packages due to an EnvironmentError: [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/robotframework_ride-1.5.2.1.dist-info' Consider using the --user option or check the permissions.

I tried with the permission thing but I am still unable to solve the issue.

I googled the solution but couldn't find an exact solution to this issue.