Pop is your friend.

slapos/recipe/mkdirectory.py

@@ -33,12 +33,7 @@ class Recipe(GenericBaseRecipe):
   def _options(self, options):
     self.directory = options.copy()
     del self.directory['recipe']
-
-    str_mode = '0700'
-    if 'mode' in self.directory:
-      str_mode = self.directory['mode']
-      del self.directory['mode']
-    self.mode = int(str_mode, 8)
+    self.mode = int(self.directory.pop('mode', '700'), 8)
 
   def install(self):