import _winreg
import os

def walkRegistry(regkey, keyToSet="file_locations", valueToSet="temp_dir",
                  HKEY=_winreg.HKEY_CURRENT_USER, verbose=False):
    """Recursively search the Windows registry, starting at top <regkey>.
    Return a list of three tuples that contain the registry key, the value
    and the associated data"""
    if verbose:
        print regkey
    i = 0
    aReg = _winreg.OpenKey(HKEY, regkey)
    try:
        while True:
            key = _winreg.EnumKey(aReg, i)
            i += 1
            if key:
                new_regkey = os.path.join(regkey, key)
                if key == keyToSet:
                    if verbose:
                        print "---> FOUND!!", new_regkey, key, keyToSet, valueToSet
                    with _winreg.OpenKey(HKEY, new_regkey) as anotherReg:
                        value_data = _winreg.QueryValueEx(anotherReg, valueToSet)[0]
                    yield new_regkey, valueToSet, value_data
                for x in walkRegistry(new_regkey, keyToSet, valueToSet, HKEY, verbose):
                    yield x
    except WindowsError:
        pass

def setRegistry(regkey, value, data, HKEY=_winreg.HKEY_CURRENT_USER):
    """Set <value> (subkey) of <regkey> with <data>"""
    hkey = [item for item in dir(_winreg) if getattr(_winreg, item) == HKEY][0]
    print "setting value '%s' with data '%s' in regkey\n'%s\\%s'\n" % \
          (value, data, hkey, regkey)
    try:
        aReg = _winreg.OpenKey(HKEY, regkey, 0, _winreg.KEY_ALL_ACCESS)
    except:
        aReg = _winreg.CreateKey(HKEY, regkey)
    try:
        _winreg.SetValueEx(aReg, value, 0, _winreg.REG_SZ, data)
    finally:
        _winreg.CloseKey(aReg)

if __name__ == "__main__":
    regkey = u"Software\\Microsoft\\Windows\\CurrentVersion\\Explorer"
    args = regkey, u"Shell Folders", u"Cookies"
    regdata = [(regkey, value, data) for regkey, value, data in walkRegistry(*args)]
    if len(regdata) == 1:
        regkey, value, existing_data = regdata[0]
        new_data = os.getenv("temp")
        setRegistry(regkey, value, new_data)