Python读取环境变量的方法和自定义类分享

使用os.environ来读取和修改环境变量：

import os

print (os.environ["temp"])

mydir = "c:\\mydir"
os.environ["mydir"] = mydir
print (os.environ["mydir"])

pathv = os.environ["path"]
print (pathv)
os.environ["path"]= mydir + ";" + os.environ["path"]
print (os.environ["path"])

自定义的python的环境变量类：

import os

class myenv:

  def __init__(self):
    self.envfile = "c:\\myenv.txt"
    self.envs = {}
 
  def setenvfile(self, filename) :
    self.envfile = filename
       
  def save(self) :
    outf = open(self.envfile, "w")
    if not outf:
      print ("env file cannot be opened for write!")
    for k, v in self.envs.items() :
      outf.write(k + "=" + v + "\n")
    outf.close()
   
  def load(self) :
    inf = open(self.envfile, "r")
    if not inf:
      print ("env file cannot be opened for open!")
    for line in inf.readlines() :
      k, v = line.split("=")
      self.envs[k] = v
    inf.close()
   
  def clearall(self) :
    self.envs.clear()
   
  def addenv(self, k, v) :
    self.envs[k] = v
   
  def removeenv(self, k) :
    del self.envs[k]
   
  def printall(self) :
    for k, v in self.envs.items():
      print ( k + "=" + v )
  
if __name__ == "__main__" :
  myenv = myenv()
  myenv.setenvfile("c:\\myenv.txt")
  myenv.load()
  myenv.addenv("mydir", "c:\\mydir")
  myenv.addenv("mydir2", "c:\\mydir2")
  myenv.addenv("mydir3", "c:\\mydir3")
  myenv.save()
  myenv.printall()