How to Use a StringVar Object in an Entry Widget in Tkinter?
If you are developing a GUI application with Python using Tkinter, then you might have come across the Entry widget. It is a widget that allows users to enter text or values into your application. While the Entry widget is useful, it can be challenging to retrieve the values input by the user. However, Tkinter provides a StringVar object to make it easier to access the text entered by the user. In this article, we’ll discuss how to use a StringVar object in an Entry widget in Tkinter.
Creating an Entry Widget with Tkinter
Before we move on to using the StringVar object with the Entry widget, we need to create an Entry widget. We can create the widget using the following code:
from tkinter import *
root = Tk()
# Create an Entry widget
entry_widget = Entry(root)
entry_widget.pack()
root.mainloop()
In this code, we first import Tkinter and create the main window using the Tk()
method. Then we create an Entry widget using the Entry()
method and pack it using the pack()
method. Finally, we start the main event loop using mainloop()
method.
Using StringVar with Entry Widget
The StringVar
object is a special variable in Tkinter that can store text or string values. We can use this object to retrieve the value of the Entry widget. To use the StringVar
object, we need to create an instance of StringVar
and pass it as the textvariable
attribute of the Entry widget. Here is an example code:
from tkinter import *
root = Tk()
# Create a StringVar object
string_var = StringVar()
# Create an Entry widget with StringVar
entry_widget = Entry(root, textvariable=string_var)
entry_widget.pack()
root.mainloop()
In this code, we first create an instance of StringVar
using the StringVar()
method. Then we create an Entry widget and pass the textvariable
attribute as string_var
. This connects the StringVar
object to the Entry widget.
Retrieving the Text from Entry Widget
To retrieve the text from the Entry widget, we need to access the get()
method of the StringVar
object. Here is an example code:
from tkinter import *
root = Tk()
# Create a StringVar object
string_var = StringVar()
# Create an Entry widget with StringVar
entry_widget = Entry(root, textvariable=string_var)
entry_widget.pack()
# Function to retrieve text from Entry widget
def get_text():
text = string_var.get()
print(text)
# Create a Button to retrieve text
button = Button(root, text="Get Text", command=get_text)
button.pack()
root.mainloop()
In this code, we first create an instance of StringVar
. Then we create an Entry widget with textvariable
as string_var
. We also define a function get_text()
that retrieves the text from the StringVar
object associated with the Entry widget. Finally, we create a Button
widget that calls the get_text()
function.
Complete Code Example
Here is a complete code example that demonstrates how to use a StringVar
object in an Entry widget in Tkinter:
from tkinter import *
root = Tk()
# Create a StringVar object
string_var = StringVar()
# Create an Entry widget with StringVar
entry_widget = Entry(root, textvariable=string_var)
entry_widget.pack()
# Function to retrieve text from Entry widget
def get_text():
text = string_var.get()
print(text)
# Create a Button to retrieve text
button = Button(root, text="Get Text", command=get_text)
button.pack()
root.mainloop()
Conclusion
In this article, we discussed how to use the StringVar
object in an Entry widget in Tkinter. We saw how to create an Entry widget, connect it to a StringVar
object, and retrieve the text entered by the user. With the StringVar
object, you can simplify the process of accessing the text from an Entry widget and make your Tkinter GUI applications more user-friendly.