Python | setting and retrieving values of Tkinter variable

Tkinter supports some variables which are used to manipulate the values of Tkinter widgets. These variables work like normal variables. 
set() and get() methods are used to set and retrieve the values of these variables. 
The values of these variables can be set using set() method or by using constructor of these variables.
There are 4 tkinter variables. 

• BooleanVar()
• StringVar()
• IntVar()
• DoubleVar()

Setting values of Tkinter variables –

1. Using variable’s constructor
Syntax:

var = Tkinter_variable(master, value = any_value)

Python3

# importing tkinter module
from tkinter import *

# creating Tk() variable
# required by Tkinter classes
master = Tk()

# Tkinter variables
# initialization using constructor
intvar = IntVar(master, value = 25, name ="2")
strvar = StringVar(master, "Hello !")
boolvar = BooleanVar(master, True)
doublevar = DoubleVar(master, 10.25)

2. Using set() method
Syntax:

var = Tkinter_variable(master=None)
var.set(value)

Python3

# importing tkinter module
from tkinter import *

# creating Tk() variable
# required by Tkinter classes
master = Tk()

# Declaration of Tkinter variables
intvar = IntVar()
strvar = StringVar()
boolvar = BooleanVar()
doublevar = DoubleVar()

# Initialization of Tkinter variables
# using set() method
intvar.set(100)
strvar.set("GFG")
boolvar.set(False)
doublevar.set(10.36)

3. Using setvar() method
Syntax:

var = Tkinter_variable(master = None, name = "NAME")
master.setvar(name="NAME", value = any_value)

NOTE: When using this method name parameter is required (mandatory).

Python3

# importing tkinter module
from tkinter import *

# creating Tk() variable
# required by Tkinter classes
master = Tk()

# Tkinter variables
# Giving user defined names to each variables
# so that variables can be modified easily
intvar = IntVar(master, name ="int")
strvar = StringVar(master, name ="str")
boolvar = BooleanVar(master, name ="bool")
doublevar = DoubleVar(master, name ="float")

# Setting values of variables
# using setvar() method
master.setvar(name ="int", value = 100)
master.setvar(name ="str", value ="GFG")
master.setvar(name ="bool", value = False)
master.setvar(name ="float", value = 1.236)

Retrieving values of tkinter variables –

1. Using get() method
Syntax:

tkinter_variable.get()

Python3

# importing tkinter module
from tkinter import *

# creating Tk() variable
# required by Tkinter classes
master = Tk()

# Tkinter variables
# Giving user defined names to each variables
# so that variables can be modified easily
intvar = IntVar(master, name ="int")
strvar = StringVar(master, name ="str")
boolvar = BooleanVar(master, name ="bool")
doublevar = DoubleVar(master, name ="float")

# Setting values of variables
# using setvar() method
master.setvar(name ="int", value = 100)
master.setvar(name ="str", value ="GFG")
master.setvar(name ="bool", value = False)
master.setvar(name ="float", value = 1.236)

# getting values of each variables using get() method
print("Value of IntVar()", intvar.get())
print("Value of StringVar()", strvar.get())
print("Value of BooleanVar()", boolvar.get())
print("Value of DoubleVar()", doublevar.get())

2. Using getvar() method
Syntax:

var = Tkinter_variable(master, name = "NAME")
master.getvar(name = "NAME")

NOTE: When using this method name parameter is required (mandatory).

Python3

# importing tkinter module
from tkinter import *

# creating Tk() variable
# required by Tkinter classes
master = Tk()

# Tkinter variables
# Giving user defined names to each variables
# so that variables can be modified easily
intvar = IntVar(master, name ="int")
strvar = StringVar(master, name ="str")
boolvar = BooleanVar(master, name ="bool")
doublevar = DoubleVar(master, name ="float")

# Setting values of variables
# using setvar() method
master.setvar(name ="int", value = 100)
master.setvar(name ="str", value ="GFG")
master.setvar(name ="bool", value = False)
master.setvar(name ="float", value = 1.236)

# getting values of each variables using getvar() method
print("Value of IntVar()", master.getvar(name ="int"))
print("Value of StringVar()", master.getvar(name ="str"))
print("Value of BooleanVar()", master.getvar(name ="bool"))
print("Value of DoubleVar()", master.getvar(name ="float"))

Output:

Value of IntVar() 100
Value of StringVar() GFG
Value of BooleanVar() False
Value of DoubleVar() 1.236