Eclipse, PyDev "Project interpreter not specified”

On my Mac 10.11.3, using LiClipse 2.5.3 I solved it with these steps:

Open a terminal window and type which python

In my case it replied with /usr/bin/python

Calling python it informed me I was using version 2.7.10.

Next I called LiClipse and went LiClipse -> Preferences -> PyDev -> Interpreters -> Python Interpreter -> New

For "Interpreter Name" I used "Python 2.7.10", although I am aware that is just a sym link and it could be updated any time. For "Interpreter Executable" I entered "/usr/bin/python"

Then "Ok"

After that, the error message went away.

In my case it has worked with following steps

Prerequisite: Python should be installed

1. Go to Window -> Preferences -> PyDev -> Interpreters and click on "Python Interpreter".
2. Then click on new button and add python executable location.

Example for windows:

c:\python2.7\python.exe

example for ubuntu:

/usr/bin/python

3. Then you can attached image and click on finish.

It should work.