I know you do this is for security。however I had to change it if I had been installed the python and others with root.It is common in China..
just like  : 


        [Errno 13] Permission denied: '/usr/local/lib/python2.7/dist-packages/te
st-easy-install-6964.write-test'

    The installation directory you specified (via --install-dir, --prefix, or
    the distutils default setting) was:

        /usr/local/lib/python2.7/dist-packages/

    Perhaps your account does not have write access to this directory?  If the
    installation directory is a system-owned directory, you may need to sign in
    as the administrator or "root" account.  If you do not have administrative
    access to this machine, you may wish to choose a different installation
    directory, preferably one that is listed in your PYTHONPATH environment
    variable.

    For information on other options, you may wish to consult the
    documentation at:

      https://pythonhosted.org/setuptools/easy_install.html

    Please make the appropriate changes for your system and try again.

    Complete output from command /usr/bin/python -c "import setuptools; __file__
='/home/bistu/edx_all/edx-platform/common/lib/calc/setup.py'; exec(compile(open(
__file__).read().replace('\r\n', '\n'), __file__, 'exec'))" develop --no-deps:
    running develop

error: can't create or remove files in install directory