code: def exists(self, table=None):
          
          if not os.path.isdir(self.root):
              return False
          if not os.path.isfile(os.path.join(self.root, _relations_filename)):
              return False
          if table is not None:
              try:
                  _table_filename(os.path.join(self.root, table))
              except ItsdbError:
                  return False
          return True
docs: Return True if the profile or a table exist.
  
          If *table* is `None`, this function returns True if the root
          directory exists and contains a valid relations file. If *table*
          is given, the function returns True if the table exists as a
          file (even if empty). Otherwise it returns False.