I want to change the value of a variable just with a button, i don’t want to create a new entire function just like that:
from Tkinter import *
variable = 1
def makeSomething():
global variable
variable = 2
root = Tk()
myButton = Button(root, text='Press me',command=makeSomething).pack()
How i can do that? (I need to do that for six buttons, making six functions it’s not an option)
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Answer
i need to make this for 6 buttons…
If each button modifies the same global variable, then have make_something
accept a value
parameter:
from tkinter import Tk, Button
variable = 1
def make_something(value):
global variable
variable = value
root = Tk()
Button(root, text='Set value to four',command=lambda *args: make_something(4)).pack()
Button(root, text='Set value to eight',command=lambda *args: make_something(8)).pack()
Button(root, text='Set value to fifteen',command=lambda *args: make_something(15)).pack()
#...etc
If each button modifies a different global, then condense all your globals into a single global dict, which make_something
can then modify.
from tkinter import Tk, Button
settings = {"foo": 1, "bar": 1, "baz": 1}
def make_something(name):
settings[name] = 2
root = Tk()
Button(root, text='Set foo',command=lambda *args: make_something("foo")).pack()
Button(root, text='Set bar',command=lambda *args: make_something("bar")).pack()
Button(root, text='Set baz',command=lambda *args: make_something("baz")).pack()
#...etc
In either case, you still only require one function.
If lambdas aren’t to your taste, you could use nested functions to create separate callables for each command:
from tkinter import Tk, Button
settings = {"foo": 1, "bar": 1, "baz": 1}
def make_callback(key):
def make_something(*args):
settings[key] = 2
return make_something
root = Tk()
Button(root, text='Set foo',command=make_callback("foo")).pack()
Button(root, text='Set bar',command=make_callback("bar")).pack()
Button(root, text='Set baz',command=make_callback("baz")).pack()
#...etc
… And you can avoid globals by instead using attributes of a class instance:
from tkinter import Tk, Button
class GUI:
def __init__(self):
self.settings = {"foo": 1, "bar": 1, "baz": 1}
self.root = Tk()
Button(self.root, text='Set foo',command=self.make_callback("foo")).pack()
Button(self.root, text='Set bar',command=self.make_callback("bar")).pack()
Button(self.root, text='Set baz',command=self.make_callback("baz")).pack()
#...etc
def make_callback(self, key):
def make_something(*args):
self.settings[key] = 2
return make_something
gui = GUI()
By the way, don’t do this:
myButton = Button(root).pack()
This assigns the result of pack()
to myButton, so myButton will be None
instead of referring to your button. Instead, do:
myButton = Button(root)
myButton.pack()