Error while importing modules in Python3

Question

I tried to smoothly pass from python 2.7 to python 3.X (3.5.2). This is a two-step question so I tried to make it clear.

1. I made a simple trial with

import numpy as np

(I did a python3 -m pip install numpy first) But I received the following error message

  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.7/dist-packages/numpy/__init__.py", line 180, in <module>
    from . import add_newdocs
  File "/usr/lib/python2.7/dist-packages/numpy/add_newdocs.py", line 13, in <module>
    from numpy.lib import add_newdoc
  File "/usr/lib/python2.7/dist-packages/numpy/lib/__init__.py", line 8, in <module>
    from .type_check import *
  File "/usr/lib/python2.7/dist-packages/numpy/lib/type_check.py", line 11, in <module>
    import numpy.core.numeric as _nx
  File "/usr/lib/python2.7/dist-packages/numpy/core/__init__.py", line 14, in <module>
    from . import multiarray
ImportError: cannot import name 'multiarray'

Is the erorr somehow connected with python2.7 ?

2. When I tried to import modules I already installed ( pip install module ) python3 do not find them ( ImportError: No module named ... ). In this second case I think that the directory in which I install the modules is connected with python 2.7. How can I point python3 to modules I already have? My dream is to avoid using python3 -m pip install ModuleName , I would like to not reinstall each single modules by hands (I also do not remember which I have and why :) ).

I am using Ubuntu 16.04.1 LTS. In my .bashrc I have the following segment, maybe is not important, but I try to give more informations as possible

 # added by me for the python import module installed outside anaconda2 (i.e.: pygtk)

export PYTHONPATH="${PYTHONPATH}:/usr/lib/python2.7/dist-packages/"
export PYTHONPATH="${PYTHONPATH}:/usr/lib/python2.7/dist-packages/glib/"

Many thanks.

Answer 1

You should definitely not have those lines in your .bashrc. Remove them and start a new shell.

And no, you need to reinstall the modules you need for Python3.