tkinter: Passing arguments when binding keys to functions

Tim Daneliuk tundra at tundraware.com
Fri Jan 10 22:30:11 CET 2003


Abel Daniel wrote:
> Tim Daneliuk (tundra at tundraware.com) wrote:
> [...snipped...] 
> 
>>for x in range(len(array)):
>>    y = array[x]	
>>    widget.bind('<F' + str(x+1) + '>', lambda arg=y : CommonHandler(arg))
> 
> [...more snipped...] 
> 
>>So, I guess the heart of my question becomes, "Why does this formulation
>>pass the event object, not the array member to CommonHandler()>"
> 
> Because the callback will get the event object as a parameter. (And that
> overwrites the default argument.)
> 
> you need:
>      widget.bind('<F' + str(x+1) + '>', lambda e, arg=y : CommonHandler(arg))
> 
> 
> abli
> abli at freemail.hu
> 

Aha! That explains it.  There is a minor error in your example, I believe.
Shouldn't the code be:

widget.bind('<F' + str(x+1) + '>', lambda e, arg=y : CommonHandler(e, arg))
                                                                   ^^^

-- 
------------------------------------------------------------------------------
Tim Daneliuk
tundra at tundraware.com





More information about the Python-list mailing list