Downgrading numpy 1.12.1 to 1.10.1

I am very new to Unix and this may be a basic question but I couldn't figure out. $ python -c "import numpy; print(numpy.version.version)" 1.12.1 $ pip uninstall numpy==1.12.1 Cannot uninstall requirement numpy, not installed $ pip install numpy==1.10.1 Collecting numpy==1.10.1 Using cached numpy-1.10.1-cp27-none-macosx_10_6_intel.macosx_10_9_intel.macosx_10_9_x86_64.macosx_10_10_intel.macosx_10_10_x86_64.whl Installing collected packages: numpy Successfully installed numpy-1.10.1 $ python -c "import numpy; print(numpy.version.version)" 1.12.1 There are three python installed in this computer and the first one is default. /sw/bin/python /usr/local/bin/python /usr/bin/python I tried changing path to use different python but all of them show numpy 1.12.1 when I cannot even uninstall because it's not installed. Anyone has any clue? ---------- Update I tried updating numpy then, `$ pip show numpy Name: numpy Version: 1.13.0rc2 Summary: NumPy: array processing for numbers, strings, records, and objects. Home-page: http://www.numpy.org Author: NumPy Developers Author-email: numpy-discussion@python.org License: BSD Location: /Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/site-packages/numpy-1.13.0rc2-py2.7-macosx-10.6-intel.egg Requires: ` `$ python -c "import numpy; print(numpy.version.version)" 1.12.1` I don't have permission to remove 1.13.0 So does this mean that my current python is running with numpy 1.13.0?