returning 2 values from a func

Question

Anyone has an idea why the following code generates error??

I call a func to get mouse coordinates:

def button_click(event):
    x, y = event.x, event.y
    print('{}, {}'.format(x, y))
    return x, y

and then I want to assign the results to new variables in main:

x_cord, y_cord = app_root.bind('<ButtonRelease-1>', button_click)

by doing this I get the following error:

"x_cord, y_cord = app_root.bind('<ButtonRelease-1>', button_click)
ValueError: too many values to unpack"

Anyone has an idea why this is happening? Thank you everybody!

app_root is my main thing. I start the program with: def main(): app_root = Tk() — Dimitrios Evangelopoulos, Feb 13 '16 at 23:23
i am not sure..... from the Tkinter documentatin: widget.bind(event, handler) If an event matching the event description occurs in the widget, the given handler is called with an object describing the event. — Dimitrios Evangelopoulos, Feb 13 '16 at 23:28

alecxe · Answer 1 · 2016-02-13T23:30:22.693

1

Assuming you are using Tkinter, bind() would only bind an event to your button_click callback and return an event identifier. Quote from the bind() docstring:

Bind will return an identifier to allow deletion of the bound function with unbind without memory leak.

You cannot expect bind() to return what your button_click() event handler returns.

edited Feb 13 '16 at 23:30

answered Feb 13 '16 at 23:26

alecxe

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In other words, `bind` was not designed to return a coordinate tuple. – Malik Brahimi Feb 13 '16 at 23:29

score -2 · Accepted Answer · answered Feb 13 '16 at 23:33

-2

It is bad practice but you can declare the scope of variables as global to access them elsewhere:

def button_click(event):

    global x, y

    x = event.x
    y = event.y

answered Feb 13 '16 at 23:33

Malik Brahimi

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returning 2 values from a func

2 Answers2