CODEWITHSUNDEEP
pythontkinter
editate
editate

Reputation: 703

Changing the text on a label

I am having trouble with using a key binding to change the value of a label or any parameter. This is my code:

from tkinter import*

class MyGUI:
  def __init__(self):
    self.__mainWindow = Tk()
    #self.fram1 = Frame(self.__mainWindow)
    self.labelText = 'Enter amount to deposit'
    self.depositLabel = Label(self.__mainWindow, text = self.labelText)
    self.depositEntry = Entry(self.__mainWindow, width = 10)
    self.depositEntry.bind('<Return>', self.depositCallBack)
    self.depositLabel.pack()
    self.depositEntry.pack()
        
    mainloop()
    
  def depositCallBack(self,event):
    self.labelText = 'change the value'
    print(self.labelText)
    
myGUI = MyGUI()

When I run this, I click the entrybox and hit enter, hoping that the label will change value to 'change the value'. However, while it does print that text, the label remains unchanged.

From looking at other questions on similar problems and issues, I have figured how to work with some of this outside a class, but I'm having some difficulties with doing it inside a class.

Upvotes: 70

Views: 259134

Answers (6)

Jake Yang
Jake Yang

Reputation: 41

Here is another one, I think. Just for reference. Let's set a variable to be an instantance of class StringVar

If you program Tk using the Tcl language, you can ask the system to let you know when a variable is changed. The Tk toolkit can use this feature, called tracing, to update certain widgets when an associated variable is modified.

There’s no way to track changes to Python variables, but Tkinter allows you to create variable wrappers that can be used wherever Tk can use a traced Tcl variable.

text = StringVar()
self.depositLabel = Label(self.__mainWindow, text = self.labelText, textvariable = text)
#                                                                   ^^^^^^^^^^^^^^^^^^^
def depositCallBack(self,event):
    text.set('change the value')

Upvotes: 2

psyFi
psyFi

Reputation: 759

You can also define a textvariable when creating the Label, and change the textvariable to update the text in the label. Here's an example:

labelText = StringVar()
depositLabel = Label(self, textvariable=labelText)
depositLabel.grid()

def updateDepositLabel(txt) # you may have to use *args in some cases
    labelText.set(txt)

There's no need to update the text in depositLabel manually. Tk does that for you.

Upvotes: 28

Umang Suthar
Umang Suthar

Reputation: 101

Use the config method to change the value of the label:

top = Tk()

l = Label(top)
l.pack()

l.config(text = "Hello World", width = "50")

Upvotes: 9

falsetru
falsetru

Reputation: 368894

self.labelText = 'change the value'

The above sentence makes labelText change the value, but not change depositLabel's text.

To change depositLabel's text, use one of following setences:

self.depositLabel['text'] = 'change the value'

OR

self.depositLabel.config(text='change the value')

Upvotes: 103

Darren Samora
Darren Samora

Reputation: 31

There are many ways to tackle a problem like this. There are many ways to do this. I'm going to give you the most simple solution to this question I know. When changing the text of a label or any kind of wiget really. I would do it like this.

Name_Of_Label["text"] = "Your New Text"

So when I apply this knowledge to your code. It would look something like this.

from tkinter import*

class MyGUI:
   def __init__(self):
    self.__mainWindow = Tk()
    #self.fram1 = Frame(self.__mainWindow)
    self.labelText = 'Enter amount to deposit'
    self.depositLabel = Label(self.__mainWindow, text = self.labelText)
    self.depositEntry = Entry(self.__mainWindow, width = 10)
    self.depositEntry.bind('<Return>', self.depositCallBack)
    self.depositLabel.pack()
    self.depositEntry.pack()

    mainloop()

  def depositCallBack(self,event):
    self.labelText["text"] = 'change the value'
    print(self.labelText)

myGUI = MyGUI()

If this helps please let me know!

Upvotes: 1

Harun ERGUL
Harun ERGUL

Reputation: 5942

I made a small tkinter application which is sets the label after button clicked

#!/usr/bin/env python
from Tkinter import *
from tkFileDialog import askopenfilename
from tkFileDialog import askdirectory


class Application:
    def __init__(self, master):
        frame = Frame(master,width=200,height=200)
        frame.pack()

        self.log_file_btn = Button(frame, text="Select Log File", command=self.selectLogFile,width=25).grid(row=0)
        self.image_folder_btn = Button(frame, text="Select Image Folder", command=self.selectImageFile,width=25).grid(row=1)
        self.quite_button = Button(frame, text="QUIT", fg="red", command=frame.quit,width=25).grid(row=5)

        self.logFilePath =StringVar()
        self.imageFilePath = StringVar()
        self.labelFolder = Label(frame,textvariable=self.logFilePath).grid(row=0,column=1)
        self.labelImageFile = Label(frame,textvariable = self.imageFilePath).grid(row = 1,column=1)

        def selectLogFile(self):
            filename = askopenfilename()
            self.logFilePath.set(filename)

        def selectImageFile(self):
            imageFolder = askdirectory()
            self.imageFilePath.set(imageFolder)

root = Tk()
root.title("Geo Tagging")
root.geometry("600x100")
app = Application(root)
root.mainloop()

Upvotes: 1

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