[python] ImportError: No module named sklearn.cross_validation

I am using python 2.7 in Ubuntu 14.04. I installed scikit-learn, numpy and matplotlib with these commands:

sudo apt-get install build-essential python-dev python-numpy \
python-numpy-dev python-scipy libatlas-dev g++ python-matplotlib \
ipython

But when I import these packages:

from sklearn.cross_validation import train_test_split

It returns me this error:

ImportError: No module named sklearn.cross_validation

What I need to do?

sklearn.cross_validation is now changed to sklearn.model_selection

Just use

from sklearn.model_selection import train_test_split

I think that will work.

Past : from sklearn.cross_validation (This package is deprecated in 0.18 version from 0.20 onwards it is changed to from sklearn import model_selection).

Present: from sklearn import model_selection

Example 2:

Past : from sklearn.cross_validation import cross_val_score (Version 0.18 which is deprecated)

Present : from sklearn.model_selection import cross_val_score

If you have code that needs to run various versions you could do something like this:

import sklearn
if sklearn.__version__ > '0.18':
    from sklearn.model_selection import train_test_split
else:
    from sklearn.cross_validation import train_test_split

This isn't ideal though because you're comparing package versions as strings, which usually works but doesn't always. If you're willing to install packaging, this is a much better approach:

from packaging.version import parse
import sklearn
if parse(sklearn.__version__) > parse('0.18'):
    from sklearn.model_selection import train_test_split
else:
    from sklearn.cross_validation import train_test_split

train_test_split is part of the module sklearn.model_selection, hence, you may need to import the module from model_selection

Code:

from sklearn.model_selection import train_test_split

sklearn.cross_validation is now changed to sklearn.model_selection

Just change

sklearn.cross_validation

to

sklearn.model_selection

I guess cross selection is not active anymore. We should use instead model selection. You can write it to run, from sklearn.model_selection import train_test_split

Thats it.

change the code like this

# from sklearn.cross_validation import train_test_split
from sklearn.model_selection import train_test_split

May be it's due to the deprecation of sklearn.cross_validation. Please replace sklearn.cross_validation with sklearn.model_selection

Ref- https://github.com/amueller/scipy_2015_sklearn_tutorial/issues/60

Splitting the dataset into the Training set and Test set

from sklearn.model_selection import train_test_split

Make sure you have Anaconda installed and then create a virtualenv using conda. This will ensure all the imports work

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>>> from sklearn.cross_validation import train_test_split

train_test_split is now in model_selection. Just type:

from sklearn.model_selection import train_test_split

it should work

sklearn.cross_validation

has changed to

sklearn.model_selection

Checkout the documentation here: https://scikit-learn.org/stable/modules/cross_validation.html

cross_validation was deprecated some time ago, try switching it out with model_selection