Jean-Michel Pichavant wrote:
chen zeguang wrote:
code is in the end.
I want to print different number when pressing different button.
Yet the program outputs 8 no matter which button is pressed.
I guess it's because the callback function is not established untill
the button is pressed, and i has already reached to 8.
then How to add callbacks that is the same function with different
argument?
CODE:
from Tkinter import *
root = Tk()
def func(x):
print x
return
func_en=[]
for i in range(9):
func_en.append(lambda:func(i))
for i in range(9):
func_en[i]()
for i in range(9):
Button(root, text='%d'%i, command=func_en[i]).pack()
from Tkinter import *
root = Tk()
def func(x):
def _printme():
print x
return _printme
for i in range(9):
Button(root, text='%d'%i, command=func(i)).pack()
Surely someone will explain why your code was not working, I can't
'cause I don't use lambda, it brings more problems than it solves
(maybe I'm not talented enough).
Above is how I would have written the code, I tested it, looks like
it's working.
JM
This solution works because of the nested function. Chen could do the
same with nested lambdas, or by using default arguments in the lambda.
The trick is just that you need separate instances of x for each
callback, so they don't all get incremented in the loop.
DaveA
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