190 def lookup_reg(key, valname=None, scope=None):

   191     ''' Look up a key/value name in the Windows registry.

   192 

   193     valname: value name. If unspecified, the default value for the key

   194     is used.

   195     scope: optionally specify scope for registry lookup, this can be

   196     a sequence of scopes to look up in order. Default (CURRENT_USER,

   197     LOCAL_MACHINE).

   198     '''

   199     try:

   200         from _winreg import HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, \

   201             QueryValueEx, OpenKey

   202     except ImportError:

   203         return None

   204 

   205     def query_val(scope, key):

   206         try:

   207             keyhandle = OpenKey(scope, key)

   208             return QueryValueEx(keyhandle, valname)[0]

   209         except EnvironmentError:

   210             return None

   211 

   212     if scope is None:

   213         scope = (HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE)

   214     elif not isinstance(scope, (list, tuple)):

   215         scope = (scope,)

   216     for s in scope:

   217         val = query_val(s, key, valname)

   218         if val is not None:

   219             return val

   220