Cannot import scikits-learn even though it seems to be installed

Got same problem, @Alan gave correct solution but hard way.Here are easy steps to resolve issue, as i am on mac osx, giving steps for same.

Ameys-Mac-mini:~ amey$ python --versionPython 2.7.2Ameys-Mac-mini:~ amey$ cd /Library/Python/2.7/site-packages/Ameys-Mac-mini:site-packages amey$ brew install gccAmeys-Mac-mini:site-packages amey$ sudo pip install -t . numpy scipy scikit-learn 

Thanks folks (see comment thread under the question)! It turns out that I have two versions of Python under my Mac's /Library/Frameworks/Python.framework directory tree: 2.7 (came with OSX) and 7.3 (installed by EPD Free).

It turns out pip put scikit-learn under 2.7 when I really wanted it under 7.3.

Changing directories to site-packages under the desired version of Python, and invoking pip install -t . {package-name} suffices to install package-name under the desired version of Python.

POSTLUDE (Feb 2021):Looking back on this question from almost 9 years ago, I think I was running into a version of this XKCD comic.

Nowadays, for dependency management of Python data engineering libraries like scikit, I'm happy with just using conda and pyenv.

In my case, my python extension has installed all in

/Library/Python/2.7/site-packages/ 

After I use the command given by the official site

pip install -U numpy scipy scikit-learn

the scikit-learn package was actually installed in my

/usr/local/lib/python2.7/site-packages

So I copied all the packages in second to the first directory, then I can import the sklearn package.