This is if you are building a package and you are finding error in imports. I learnt it the hard way.The answer isn't to add the package to python path or to do it programatically (what if your module gets installed and your command adds it again?) thats a bad way.
The right thing to do is: 1) Use virtualenv pyvenv-3.4 or something similar 2) Activate the development mode - $python setup.py develop