Question

I get the error “NameError: global name ‘entryWidget’ is not defined” in the following piece of Python 3 tkinter code:

from tkinter import *
import tkinter

def displayText():
    tkinter.messagebox.showinfo("Tkinter Entry Widget", "Text value =" + entryWidget)

class Application(Frame):

    def createWidgets(self):

        root.title("TITLE")

        textFrame = Frame(root)
        entryLabel = Label(textFrame)
        entryLabel["text"] = "Enter the text:"
        entryLabel.pack(side=LEFT)

        entryWidget = Entry(textFrame)
        entryWidget["width"] = 50
        entryWidget.pack(side=LEFT)
        textFrame.pack()
        button = Button(root, text="Submit", command=displayText)
        button.pack()

        self.QUIT = Button(self)
        self.QUIT["text"] = "QUIT"
        self.QUIT["fg"] = "red"
        self.QUIT["command"] = self.quit
        self.QUIT.pack()


    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.pack()
        self.createWidgets()

root = Tk()
app = Application(master=root)
app.mainloop()
root.destroy()

The code itself is designed to create a text box (with text next to it), an enter button for the text box and a quit button. When text is entered in the text box and enter is pressed then a message box should appear telling the user what they entered. The quit button just quits the script.

How can I fix the error I am getting (I am aware what the error means, just don’t know how to fix it in this scenario). Note that I am new to tkinter and GUI code.

Answer 1

What about something like that:

from tkinter import *
import tkinter


class Application(Frame):

    def createWidgets(self):

        root.title("TITLE")

        textFrame = Frame(root)
        entryLabel = Label(textFrame)
        entryLabel["text"] = "Enter the text:"
        entryLabel.pack(side=LEFT)

        self.entryWidget = Entry(textFrame)
        self.entryWidget["width"] = 50
        self.entryWidget.pack(side=LEFT)
        textFrame.pack()
        button = Button(root, text="Submit", command=self.displayText)
        button.pack()

        self.QUIT = Button(self)
        self.QUIT["text"] = "QUIT"
        self.QUIT["fg"] = "red"
        self.QUIT["command"] = self.quit
        self.QUIT.pack()

    def displayText(self):
        tkinter.messagebox.showinfo("Tkinter Entry Widget", "Text value =" + self.entryWidget.get())

    def __init__(self, master=None):
        Frame.__init__(self, master)
        self.pack()
        self.createWidgets()

root = Tk()
app = Application(master=root)
app.mainloop()
root.destroy()

I don’t have tkinter here so I can’t check it. But I hope it will help.