這裡有一些類似于jaraco.windows項目中的代碼的東西。與此類似，隻使用内置的Python子產品—是以不需要首先下載下傳和安裝pywin32擴充。另外，它與python2.6+和3.x相容，支援Unicode環境變量和值（本例中是目錄路徑）。在
請注意，更改永久性系統級環境變量需要Windows管理者權限。在import ctypes
from ctypes.wintypes import HWND, UINT, WPARAM, LPARAM, LPVOID
LRESULT = LPARAM # synonymous
import os
import sys
try:
import winreg
unicode = str
except ImportError:
import _winreg as winreg # Python 2.x
class Environment(object):
path = r'SYSTEM\CurrentControlSet\Control\Session Manager\Environment'
hklm = winreg.ConnectRegistry(None, winreg.HKEY_LOCAL_MACHINE)
key = winreg.OpenKey(hklm, path, 0, winreg.KEY_READ | winreg.KEY_WRITE)
SendMessage = ctypes.windll.user32.SendMessageW
SendMessage.argtypes = HWND, UINT, WPARAM, LPVOID
SendMessage.restype = LRESULT
HWND_BROADCAST = 0xFFFF
WM_SETTINGCHANGE = 0x1A
NO_DEFAULT_PROVIDED = object()
def get(self, name, default=NO_DEFAULT_PROVIDED):
try:
value = winreg.QueryValueEx(self.key, name)[0]
except WindowsError:
if default is self.NO_DEFAULT_PROVIDED:
raise ValueError("No such registry key", name)
value = default
return value
def set(self, name, value):
if value:
winreg.SetValueEx(self.key, name, 0, winreg.REG_EXPAND_SZ, value)
else:
winreg.DeleteValue(self.key, name)
self.notify()
def notify(self):
self.SendMessage(self.HWND_BROADCAST, self.WM_SETTINGCHANGE, 0, u'Environment')
Environment = Environment() # singletion - create instance
PATH_VAR = 'PATH'
def append_path_envvar(addpath):
def canonical(path):
path = unicode(path.upper().rstrip(os.sep))
return winreg.ExpandEnvironmentStrings(path) # Requires Python 2.6+
canpath = canonical(addpath)
curpath = Environment.get(PATH_VAR, '')
if not any(canpath == subpath
for subpath in canonical(curpath).split(os.pathsep)):
Environment.set(PATH_VAR, os.pathsep.join((curpath, addpath)))
def remove_envvar_path(folder):
""" Remove *all* paths in PATH_VAR that contain the folder path. """
curpath = Environment.get(PATH_VAR, '')
folder = folder.upper()
keepers = [subpath for subpath in curpath.split(os.pathsep)
if folder not in subpath.upper()]
Environment.set(PATH_VAR, os.pathsep.join(keepers))
示例用法：
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