code: def ConnectTo(self, appName, data=None):
          
          global number_of_apps_communicating
          self.ddeServerName = appName
          try:
              self.ddec = DDEClient(self.ddeServerName, self.ddeClientName) # establish conversation
          except DDEError:
              raise
          else:
              number_of_apps_communicating +=1
docs: Exceptional error is handled in zdde Init() method, so the exception
          must be re-raised