import nltk does not work

Question

So I just downloaded nltk module from the website and installed it. But when I run import nltk on the python console, I am getting this error. Can anybody help me? I've searched online for this error but to no avail.

>>> import nltk
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/local/lib/python2.7/dist-packages/nltk/__init__.py", line 128, in <module>
    from nltk.chunk import *
  File "/usr/local/lib/python2.7/dist-packages/nltk/chunk/__init__.py", line 157, in <module>
    from nltk.chunk.api import ChunkParserI
  File "/usr/local/lib/python2.7/dist-packages/nltk/chunk/api.py", line 13, in <module>
    from nltk.parse import ParserI
  File "/usr/local/lib/python2.7/dist-packages/nltk/parse/__init__.py", line 79, in <module>
    from nltk.parse.transitionparser import TransitionParser
  File "/usr/local/lib/python2.7/dist-packages/nltk/parse/transitionparser.py", line 21, in <module>
    from sklearn.datasets import load_svmlight_file
  File "/home/jaydeep/.local/lib/python2.7/site-packages/sklearn/__init__.py", line 57, in <module>
    from .base import clone
  File "/home/jaydeep/.local/lib/python2.7/site-packages/sklearn/base.py", line 11, in <module>
    from .utils.fixes import signature
  File "/home/jaydeep/.local/lib/python2.7/site-packages/sklearn/utils/__init__.py", line 10, in <module>
    from .murmurhash import murmurhash3_32
  File "numpy.pxd", line 155, in init sklearn.utils.murmurhash (sklearn/utils/murmurhash.c:5029)
**ValueError: numpy.dtype has the wrong size, try recompiling**

I have tried reinstalling both numpy and nltk but I still get the same error

Answer 1

This error is typically caused when you have an older version of numpy installed.

Try by upgrading it with pip :

sudo pip install numpy --upgrade

If you have already installed a newer numpy and still get this, its possible that you may have two versions of numpy and when you access it through python-console its pointing to the older version. This is solved here : similar issue

Your also get this because of openblas/atlas used by sklearn . As per the scikit-learn advanced installation :

using openblas can give speedups in some scikit-learn modules, but can freeze joblib/multiprocessing prior to openblas version 0.2.8-4, so using it is not recommended unless you know what you're doing.

If you do want to use openblas, then replacing atlas only requires a couple of commands. Atlas has to be removed, otherwise numpy may not work.

Source

Answer 2

Never mind. All I had to do was uninstall scikit-learn and it worked smoothly.

I don't understand why this worked. If anyone could shed some light on this it would be appreciated.

Answer 3

Recently I had the same issue in Ubuntu. Tried with upgrading numpy, uninstalled scikit-learn. Nothing works. Just restarted the system and got worked.