Hi, USE CASE ======== How to test if an "idFolder" exist in my "topFolder"? If the "idFolder" does not exist I would like to add it to "topFolder" Question ====== Who know why this code in an external method (EM) does not work? Code ==== def addFolder(self, idFolder, topFolder): self=self.this() if not hasattr(topfolder,idFolder): self.getattr(self,topFolder).manage_addFolder(idFolder) PS: How to add a folder anywhere in the ZODB tree with an EM also located anywhere? Bye, FR.