Class for setting, changing and deleting environment variables in Windows Registry

win-env-var-setter.py

# python
# Borrowing heavily from: https://stackoverflow.com/a/35286642
import winreg

class RegHandler:
    def __init__(self, reg_path: str):
        self.reg_path = reg_path

    def set_reg(self, name, value):
        try:
            winreg.CreateKey(winreg.HKEY_CURRENT_USER, self.reg_path)
            registry_key = winreg.OpenKey(winreg.HKEY_CURRENT_USER, self.reg_path, 0, 
                                        winreg.KEY_WRITE)
            winreg.SetValueEx(registry_key, name, 0, winreg.REG_SZ, value)
            winreg.CloseKey(registry_key)
            return True
        except WindowsError:
            return False

    def get_reg(self, name):
        try:
            registry_key = winreg.OpenKey(winreg.HKEY_CURRENT_USER, self.reg_path, 0,
                                        winreg.KEY_READ)
            value, regtype = winreg.QueryValueEx(registry_key, name)
            winreg.CloseKey(registry_key)
            return value
        except WindowsError:
            return None
            
    def del_reg(self, name):
        try:
            winreg.CreateKey(winreg.HKEY_CURRENT_USER, self.reg_path)
            registry_key = winreg.OpenKey(winreg.HKEY_CURRENT_USER, self.reg_path, 0, 
                                        winreg.KEY_WRITE)
            winreg.DeleteValue(registry_key, name)
            winreg.CloseKey(registry_key)
            return True
        except WindowsError:
            return False

if __name__ == '__main__':
    # Tests
    # Setting environment variables
    pairs = (('testing', 'A'), ('testing', 'B'), ('testing', 'C'), ('testing', 'B'))
    EnvHandler = RegHandler(reg_path = r'Environment')
    assert EnvHandler.get_reg('testing') is None
    for k, v in pairs:
        EnvHandler.set_reg(k, v)
        assert EnvHandler.get_reg(k) == v
    else:
        EnvHandler.del_reg(k)
        assert EnvHandler.get_reg(k) is None

    # Example set MouseSensitivity
    MouseHandler = RegHandler(reg_path = r'Control Panel\Mouse')
    mouse_sens = MouseHandler.get_reg('MouseSensitivity')
    
    MouseHandler.set_reg('MouseSensitivity', '7')
    assert MouseHandler.get_reg('MouseSensitivity') == '7'

    MouseHandler.set_reg('MouseSensitivity', '8')
    assert MouseHandler.get_reg('MouseSensitivity') == '8'

    # Reset MouseSensitivity
    MouseHandler.set_reg('MouseSensitivity', mouse_sens)