如何更正安装python时的$PATH和$PYTHONPATH

Question

这是我在终端上输入env时得到的结果。我曾多次尝试使用macports安装Python模块，但似乎没有安装。在

MANPATH=/opt/local/share/man:
TERM_PROGRAM=Apple_Terminal
TERM=xterm-256color
SHELL=/bin/bash
TMPDIR=/var/folders/vn/tz5696155bs0kywx550ltbfc0000gn/T/
COM_GOOGLE_CHROME_FRAMEWORK_SERVICE_PROCESS/USERS/SUMRANIA/LIBRARY/APPLICATION_SUPPORT/GOOGLE/CHROME_SOCKET=/tmp/launch-jTUr6q/ServiceProcessSocket
Apple_PubSub_Socket_Render=/tmp/launch-rYyBDG/Render
TERM_PROGRAM_VERSION=309
OLDPWD=/Users/sumrania/Documents/MATLAB/pythonplay
TERM_SESSION_ID=17787ECC-867D-4B18-A83C-13BB1EDB65AC
USER=sumrania
COMMAND_MODE=unix2003
SSH_AUTH_SOCK=/tmp/launch-RIICzP/Listeners
__CF_USER_TEXT_ENCODING=0x1F5:0:0
Apple_Ubiquity_Message=/tmp/launch-GXb1j4/Apple_Ubiquity_Message
PATH=/Library/Frameworks/Python.framework/Versions/2.7/bin:/opt/local/bin:/opt/local/sbin:/opt/local/bin:/opt/local/sbin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/opt/X11/bin:/usr/texbin
PWD=/Users/sumrania
LANG=en_US.UTF-8
SHLVL=1
HOME=/Users/sumrania
PYTHONPATH=/usr/local/lib/python2.7/site-packages:/usr/local/lib/python2.7/site-packages/:/usr/local/lib/python2.7/site-packages/:
LOGNAME=sumrania
DISPLAY=/tmp/launch-KREcuI/org.macosforge.xquartz:0
_=/usr/bin/env

我认为我的路径和Python路径出了问题，因为它们似乎是同一件事重复了一次又一次。我该如何纠正这一点？正确的方法是什么？在