Can't bind a function to a button

Question

I can't seem to bind my function to this certain button. I have tried this:

This is my function:

def callback(str):
    print('he button <%s> is being pressed' % str)

and this is where i bind the function:

btn = Button(text="%s" % feedList[i]['message'])
btn.bind(on_press=callback(i))

is `i` a string? because `callback()` needs a string as an argument. — George Bou, Oct 09 '17 at 19:08
no, but i tried returning a string but it still wont run e.g. on_press=callback("hello world") — xx4xx4, Oct 09 '17 at 19:16
You should give us more information then, especially the error messages you get and a code we can run and test. — George Bou, Oct 09 '17 at 19:19

score 0 · Accepted Answer · answered Oct 10 '17 at 05:38

0

You should pass function name when binding:

btn.bind(on_press=callback)

# ...

def callback(instance, value):
    print('My button <%s> state is <%s>' % (instance, value))

If you want to pass i to callback also you can use partial function:

from functools import partial

btn.bind(on_press=partial(callback, i))

# ...

def callback(i, instance, value):
    print('My button <%s> state is <%s>' % (instance, value))

answered Oct 10 '17 at 05:38

Mikhail Gerasimov

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can i ask you another question? – xx4xx4 Oct 19 '17 at 19:33

Can't bind a function to a button

1 Answers1