docs: def delete(self, symbol):
          """
          Deletes a Symbol.
          
          Parameters
          ----------
          symbol : str or Symbol
          """
          if isinstance(symbol, (str, unicode)):
              sym = self.get(symbol)
          elif isinstance(symbol, Symbol):
              sym = symbol
          else:
              raise Exception("Invalid symbol {}".format((repr(symbol))))
  
          # Has to handle the case where the table would exist already
          # and where it wouldn't.
          try:
              sym.datatable = Table(sym.name, Base.metadata, autoload=True)
              sym.datatable.drop(self.eng, checkfirst=True)
          except NoSuchTableError:
              print "No worries, {} never existed to begin with.".format(sym.name)
  
          self.ses.delete(sym)
          self.ses.commit()