...using Linux (xubuntu). How to install python2.7.3 + numpy + scipy + matplotlib + scikits.statsmodels + pandas0.7.3 correctly ? My final aim is to have them working. The problem: ~$ python --version Python 2.7.3 so i already have a system-default 2.7.3, which is good! ~$ dpkg -s python-numpy Package: python-numpy Status: install ok installed and i already have numpy installed! great! But... ~$ python Python 2.7.3 (default, Oct 23 2012, 01:07:38) [GCC 4.6.1] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import numpy as nmp Traceback (most recent call last): File "<stdin>", line 1, in <module> ImportError: No module named numpy this module couldn't be find by python. The same with scipy, matplotlib. Why? ~$ sudo apt-get install python-numpy [...] Reading package lists... Done Building dependency tree Reading state information... Done python-numpy is already the newest version. [...] why it does not see numpy and others ? update: >>> import sys >>> print sys.path ['', '/usr/local/lib/python27.zip', '/usr/local/lib/python2.7', '/usr/local/lib/python2.7/plat-linux2', '/usr/local/lib/python2.7/lib-tk', '/usr/local/lib/python2.7/lib-old', '/usr/local/lib/python2.7/lib-dynload', '/usr/local/lib/python2.7/site-packages'] >>> so i do have /usr/local/lib/python2.7 ~$ pip freeze Warning: cannot find svn location for distribute==0.6.16dev-r0 BzrTools==2.4.0 CDApplet==1.0 [...] matplotlib==1.0.1 mutagen==1.19 numpy==1.5.1 [...] pandas==0.7.3 papyon==0.5.5 [...] pytz==2012g pyxdg==0.19 reportlab==2.5 scikits.statsmodels==0.3.1 scipy==0.11.0 [...] zope.interface==3.6.1 as you can see, those modules are already installed! But! ls -la /usr/local/lib/ gives ONLY python2.7 dir. And still ~$ python -V Python 2.7.3 and import sys sys.version '2.7.3 (default, Oct 23 2012, 01:07:38) \n[GCC 4.6.1]' updated: Probably I've missed another instance... One at /usr/Python-2.7.3/ and second (seems to be installed "by hands" far far ago) at /usr/python2.7.3/Python-2.7.3/ But how two identical versions can work at the same time??? Probably, one of them is "disabled" (not used by any program, but I don't know how to check if any program uses it). ~$ ls -la /usr/bin/python* lrwxrwxrwx 1 root root 9 2011-11-01 11:11 /usr/bin/python -> python2.7 -rwxr-xr-x 1 root root 2476800 2012-09-28 19:48 /usr/bin/python2.6 -rwxr-xr-x 1 root root 1452 2012-09-28 19:45 /usr/bin/python2.6-config -rwxr-xr-x 1 root root 2586060 2012-07-21 01:42 /usr/bin/python2.7 -rwxr-xr-x 1 root root 1652 2012-07-21 01:40 /usr/bin/python2.7-config lrwxrwxrwx 1 root root 9 2011-10-05 23:53 /usr/bin/python3 -> python3.2 lrwxrwxrwx 1 root root 11 2011-09-06 02:04 /usr/bin/python3.2 -> python3.2mu -rwxr-xr-x 1 root root 2852896 2011-09-06 02:04 /usr/bin/python3.2mu lrwxrwxrwx 1 root root 16 2011-10-08 19:50 /usr/bin/python-config -> python2.7-config there is a symlink python-python2.7, maybe I can ln -f -s this link to exact /usr/Python-2.7.3/python destination without harm ?? And how correctly to remove the 'copy' of 2.7.3?