如何從注冊表中刪除Windows用戶環境變量

Question

通過此簡單的設置，我可以在注冊表中創建任何用戶環境變量：

import win32con
import win32gui
import _winreg as winreg

def set_environment_variable(variable, value, user_env=True):
    if user_env: reg_key = winreg.OpenKey(winreg.HKEY_CURRENT_USER, 'Environment', 0, winreg.KEY_SET_VALUE)
    else: reg_key = winreg.OpenKey(winreg.HKEY_LOCAL_MACHINE, r'SYSTEM\CurrentControlSet\Control\Session Manager\Environment', 0, winreg.KEY_SET_VALUE)

    if '%' in value: var_type = winreg.REG_EXPAND_SZ
    else: var_type = winreg.REG_SZ

    with reg_key:
        winreg.SetValueEx(reg_key, variable, 0, var_type, value)     
    win32gui.SendMessageTimeout(win32con.HWND_BROADCAST, win32con.WM_SETTINGCHANGE, 0, 'Environment', win32con.SMTO_ABORTIFHUNG, 1000)

創建一個MY_VARIABLE ：

set_environment_variable('MY_VARIABLE', 'MY_VALUE')

這是屏幕截圖：

問題：如何刪除剛剛創建的MY_VARIABLE ？

Answer 1

您可以使用以下方法輕松地從Windows注冊表中設置或刪除環境變量：

def set_environment_variable(variable, value, user_env=True):
    """
    Set/Remove Environment variable from windows registry.

    :param variable: Environment Variable Name
    :param value: Environment Variable Value (None to delete)
    :param user_env: if true set in user env instead of in system env
    :return: None
    """
    if user_env:
        # This is for the user's environment variables
        reg_key = winreg.OpenKey(
            winreg.HKEY_CURRENT_USER,
            'Environment', 0, winreg.KEY_SET_VALUE)
    else:
        # This is for the system environment variables
        reg_key = winreg.OpenKey(
            winreg.HKEY_LOCAL_MACHINE,
            r'SYSTEM\CurrentControlSet\Control\Session Manager\Environment',
            0, winreg.KEY_SET_VALUE)

    with reg_key:
        if value is None:
            winreg.DeleteValue(reg_key, variable)
        else:
            if '%' in value:
                var_type = winreg.REG_EXPAND_SZ
            else:
                var_type = winreg.REG_SZ
            winreg.SetValueEx(reg_key, variable, 0, var_type, value)

    # notify about environment change
    win32gui.SendMessageTimeout(
        win32con.HWND_BROADCAST, win32con.WM_SETTINGCHANGE, 0,
        'Environment', win32con.SMTO_ABORTIFHUNG, 1000)

設置環境變量：

set_environment_variable('MY_VARIABLE', 'MY_VALUE)

要刪除環境變量：

set_environment_variable('MY_VARIABLE', None)

您可以使用以下命令導入win32庫：

import win32con
import win32gui
try:
    import _winreg as winreg
except ImportError:
    # this has been renamed in python 3
    import winreg