[Tutor] newbie:Problem with arguments for methods

[alan.gauld@bt.com]

> self.hi_there = Button(frame, bitmap = "info", 
> relief="raised", command=self.say_hi(self.viewer))
> def say_hi(self, canv): 
> 
> canv.create_oval(10,20,50,60)

> Before the small changes the button would write "print this" 
> add the argument to self.say_hi it doesn't wait for me to 
> press the button.  

By putting parentheses after the say_hi you asked Python to call 
the function and put the result as the action of the command.

command=
must have a function *object*(usually the name!) as a value.

Try something like this:

command=lambda c=self.viewer: say_hi(c)

lambda creates a new function which passes an argument, c to say hi.
We set the default value to the current viewer.

HTH,

Alan G.