How to Dynamically Label my Buttons Based on Database Query using Tkinter

Question

I am trying to label my button dynamically based on the database results. So in this case the button would be labeled '23'

Database

| id | number |

| 1 | 23

from tkinter import *
import pymysql as mdb

from tkinter import ttk


#functions
def functionHolder():
    print("do nothing function holder")


root = Tk()
dbi = mdb.connect("localhost",port=3306, user="access", passwd="***", db="index_db" )
cursor = dbi.cursor()

cursor.execute("""SELECT number FROM caution_elements WHERE id = 1 """)
dbi.commit()
data = cursor.fetchone()[0]
dbi.close()

result =str("%s " % data)



 varButt = Button(root,textvariable=data, command=functionHolder)
 varButt.pack()

 root.mainloop()

Button should be labeled [23] I currently get a blank button and no errors

you don't need str("%s " % data) to convert to string - use str(data) or "%s " % data if you need space at the end. — furas
– furas, Commented Dec 6, 2017 at 1:26
textvariable= expects special class tkinter.StringVar(). If you have your numer in result then use text=result or even text=data — furas
– furas, Commented Dec 6, 2017 at 1:28
What do you mean by "labeled [23]"? Do you mean the text on the button? — Bryan Oakley
– Bryan Oakley, Commented Dec 6, 2017 at 1:44
result =str(data) varButt = Button(root,text=result, command=functionHolder) varButt.pack() Worked!!! Thanks — Raymond
– Raymond, Commented Dec 6, 2017 at 2:33

Nae · Accepted Answer · 2017-12-06 02:47:30Z

3

A textvariable option of tkinter widgets require special variable classes such as StringVar, BooleanVar or IntVar. Their values can be accessed using get method and their values can be changed using set as in:

import tkinter as tk

root = tk.Tk()

data = tk.StringVar()
data.set("This")

def change():
    if data.get() == "This":
        data.set("That")
    else:
        data.set("This")

tk.Label(root, textvariable=data).pack()
tk.Button(root, text="Change", command=change).pack()

root.mainloop()

If you are not sure about using class variables another example without them would be:

import tkinter as tk

root = tk.Tk()

data = "This"

def change():
    global data
    if data == "This":
        data = "That"
        a_label['text'] = data
    else:
        data = "This"
        a_label.config(text=data)


a_label = tk.Label(root, text=data)
a_label.pack()
tk.Button(root, text="Change", command=change).pack()

root.mainloop()

Both of the code pieces do the same thing except that when you change data's value, in the first example you're also changing text displayed by the label, and in the second example you need to explicitly update a_label's text option.

Also note that you can use a_widget.config(option=value), a_widget.configure(option=value), a_widget['option'] = value interchangeably given that you're modifying only one option.

edited Dec 6, 2017 at 2:47

answered Dec 6, 2017 at 1:31

Nae

15.5k8 gold badges62 silver badges89 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

GaryMBloom Over a year ago

Further, when you tie the Label text to a StringVar() like data, when you programmatically update the StringVar value with a call to the set() method data.set('hello'), you will see the text on the Button magically change, too. That's part of the beauty of the event-driven GUI world of Tkinter. Once configured properly, you can make a change in one place, and it can propagate throughout your GUI.

Raymond Over a year ago

Thanks that makes a lot of sense.

Collectives™ on Stack Overflow

How to Dynamically Label my Buttons Based on Database Query using Tkinter

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related