def cell_px(self, line='', cell=None):
        """Executes the cell in parallel.
        
        Examples
        --------
        ::

            In [24]: %%px --noblock
               ....: a = os.getpid()
            Async parallel execution on engine(s): all
            
            In [25]: %%px
               ....: print a
            [stdout:0] 1234
            [stdout:1] 1235
            [stdout:2] 1236
            [stdout:3] 1237
        """
        
        args = magic_arguments.parse_argstring(self.cell_px, line)
        
        if args.targets:
            save_targets = self.view.targets
            self.view.targets = self._eval_target_str(args.targets)
        try:
            return self.parallel_execute(cell, block=args.block,
                                groupby=args.groupby,
                                save_name=args.save_name,
            )
        finally:
            if args.targets:
                self.view.targets = save_targets