I am trying to hide a field based on an option selected from a drop down.

In my py file I have:

hide = fields.Boolean(string= 'Hide' , compute= "_compute_hide" )

@api.onchange( 'math_type_cfg_id' )

def _onchange_math_type_cfg_id(self):

    if self .math_type_cfg_id == '5' :

         self.hide = True

    else :

         self.hide = False

In my view I have:

<field name = "c_math_cfg_id"                                         

                                         required = "math_type_cfg_id == 5"

                                         invisible = "'[('hide', '=', True)]"                                       

                                         />

The required works but the field will not disappear.

Any help would be greatly appreciated!