Python declarative

[Francesco Bochicchio]

Some time ago I played with Tkinter trying a more declarative way of coding the GUI building part and I come out with this:

       top = Tk( 'top' ).add (
             Frame( 'frame' ).add (
                Pack( side = 'top' ),
                Frame ( 'panel1' ).add (
                    Pack( side='left'),
                    Label ( 'label', text="Entry 1 : " ),
                    Entry ( 'entry' )  
                ),
                Frame( 'panel2' ).add (
                    Pack( side='left'),
                    Label ( 'label', text="Entry 2 : " ),
                    Entry( 'entry' ) 
                ),
                Pack( side = 'bottom' ), # packing change 
                Button( 'button', 
                    text='Click Me' ))
             )

        top.frame.button["command"] = functools.partial(button_cb, top)
        top.realize().mainloop()

which, without changing the underlying plumbing, may also be written this way, which avoid nesting but still looks  declarative-ish :

   top = Tk( 'top' )
    top.add( Frame( 'frame' ) )
    top.frame.add (
        Pack( side = 'top' ),
        Frame ( 'panel1' ),
        Frame( 'panel2' ),
        Pack( side = 'bottom' ), # packing change 
        Button( 'button', 
                text='Click Me',
                command = functools.partial(button_cb, top) ) )
            
    top.frame.panel1.add(
        Pack( side='left'),
        Label ( 'label', text="Entry 1 : " ),
        Entry ( 'entry' ) ) 

    top.frame.panel2.add(
        Pack( side='left'),
        Label ( 'label', text="Entry 1 : " ),
        Entry( 'entry' )  ) 
   
    top.realize().mainloop()


The underlying plumbing for those two examples is just two classes amounting to about fifty lines of code, plus one-liner wrappers for each kind of widgets/geometry

This just to tell you that yes, with python you can write declarative-looking code ... if you don't mind parenthesis :-)