Prerequisites: Python GUI – tkinter, Python Tkinter – Validating Entry Widget
Tkinter is a Python GUI (Graphical User Interface) module which is quick and easy to implement and is widely used for creating desktop applications. It provides various basic widgets to build a GUI program. In Tkinter, Spinbox is commonly used widget to select the fixed number of values from the range provided by the programmer, but by default Spinbox accepts all types of input given by user. Hence we need to validate the input and accept only those values which are in the range.
Below is the implementation:
Note: For more information on Validatecommand, refer to Python Tkinter – Validating Entry Widget
Python3
from tkinter import *# Validating functiondef validate(user_input): # check if the input is numeric if user_input.isdigit(): # Fetching minimum and maximum value of the spinbox minval = int(root.nametowidget(spinbox).config('from')[4]) maxval = int(root.nametowidget(spinbox).config('to')[4]) # check if the number is within the range if int(user_input) not in range(minval, maxval): print ("Out of range") return False # Printing the user input to the console print(user_input) return True # if input is blank string elif user_input is "": print(user_input) return True # return false is input is not numeric else: print("Not numeric") return Falseroot = Tk()root.geometry("300x300")root.title("Spinbox Range Validation")# Creating Spinboxspinbox = Spinbox(root, from_ = 1, to = 1000)spinbox.pack()range_validation = root.register(validate)spinbox.config(validate ="key", validatecommand =(range_validation, '% P'))root.mainloop() |
Output:
