[FIXED] ModuleNotFoundError: 'sklearn' in Jupyter notebook

Issue

Using Conda (4.8) on pyhthon 3.7, on Win10. I have scikit learn installed using conda conda install scikit-learn . Tried a few things: also installed it in the env conda install -n my_env scikit-learn. Also tried installing conda install -c anaconda ipython - nothing has worked.

I can list it:

scikit-learn              0.22             py37h6288b17_0  

But in juypter notebook get error from sklearn.datasets import fetch_lfw_pairs (tried couple other commands too) ModuleNotFoundError: No module named 'sklearn'

But If I use Anaconda UI Navigator to launch notebook everything works fine

Update
I tried this command line option did not work for me, despite plenty effort and help & support from the community (as below). Meanwhile the Jupyter notebook can also be launched from the Anaconda UI itself. That always was working for me - no configuration or setup needed (none). I have not found any limitations etc with this yet (and you do get the exact same notebook). For advanced/unique use cases where you may need to fine tune your configuration cmd line could be helpful, I am not there.

Solution

Likely, you are loading the wrong kernel when you start your notebook. Here is a barebones way to set up the environment:

conda create -n testenv python=3.7 -y

conda activate testenv

conda install scikit-learn
conda install ipython
conda install notebook

python -m ipykernel install --user --name testenv

When you click on new in the browser you will have an additional option next to python3, namely the kernel you just registered. I just tested this with anaconda 4.7 and I could import sklearn.

edit:

The code in the answer creates a new python environment. Then, it installs ipython and jupyter notebook in that environment and makes sure that this environment can be used with jupyter notebook (i.e. registering the ipykernel).

Now of course besides scikit learn, no other libraries have been installed within that specific environment.

So, if you want to use more libraries, you have to go to the command line, activate the environment, and install the libraries you want to use:

conda activate testenv
conda install scipy numpy matplotlib

To then run jupyter notebook from the environment, after you have installed all the things you want (and after having closed the command prompt or having deactivated the environment), you can do

conda activate testenv
jupyter notebook

in the command prompt.

Answered By - warped