#NEWLINE# @ property #NEWLINE# def _existing_value( self ) : #NEWLINE# #INDENT# if ( self . field is not None ) : #NEWLINE# #INDENT# pd = pd . field . parent . python_data #NEWLINE# if ( self . field . name in pd ) : #NEWLINE# #INDENT# return pd [ self . field . name ] #NEWLINE# #UNINDENT# return self . model ( ) #NEWLINE# #UNINDENT# return None