python脚本中如何设置系统的环境变量

具体查看github https://github.com/double12gzh/PythonLearning/blob/master/setup_env_in_script.py 

#!/usr/bin/python

####################################################################
# Author: Jeffrey Guan
# Date: 2016-10-24
# Description: set the environment parameters in python script.
# For example, if we want to run "nova list" in python
# script before "source openrc" in CLI, we can safely
# use this script.
#
# A part of "/root/openrc" is:
# #!/bin/sh
# export LC_ALL=C
# export OS_NO_CACHE='true'
# export OS_TENANT_NAME='admin'
# export OS_PROJECT_NAME='admin'
# export OS_USERNAME='admin'
# export OS_PASSWORD='admin'
#####################################################################

import os
import re

# Open the file.
file_obj = open('/root/openrc')

try:
# Search the str started with "export" and contains "=".
patt_save_str = re.compile(r'^export.*=.*')
# Search "=".
patt_rm_str = re.compile(r'=')

# Read file content by lines.
lines = file_obj.readlines()

for line in lines:
match = patt_save_str.search(line)
if match:
# Remove the "export" and "" from match.group(0).
temp_str = match.group(0).strip("export").strip()

# Split the str into a list by "=".
environ_value_dic = patt_rm_str.split(temp_str)

# Set the value for each env parameters.
os.environ[environ_value_dic[0]] = environ_value_dic[1].strip("'")

# Print the env and values. Or we can run "env" on the CLI to check
# all env and values.
#
#print os.getenv('OS_PROJECT_NAME')

# Test nova command.
os.system('nova list')

finally:
file_obj.close()