Number Doubler using Python

In this tutorial, we will learn how to double a number using Python, with some really simple examples.

So let us start now:

 

import tkinter as tk
from tkinter import messagebox

1)Tkinter serves as Python’s official library for developing graphical user interfaces (GUIs).

2)Tk helps in improving code readability.

3)messagebox is a module present in tkinter, which helps in providing a pop-up message to indicate if there is any error.

 

def double_the_number():
    try:
        Chirag = float(entry.get())
        doubled_the_number = Chirag * 2
        result_label.config(text=f"The Doubled Number is : {doubled_the_number}")
    except ValueError:
        messagebox.showerror("Invalid input", "Please enter another valid number, as it is incorrect")

1)First lets define the function ‘double_the_number’, which in this case is used to perform a function of doubling an integer.

2)Now comes the ‘try’ block, which is used to handle errors. If there are any errors within the ‘try’ block, the program jumps to ‘except’ block to handle the error, so the program runs irrespective of an error.

3)  The code Chirag = float(entry.get()) extracts the input provided by the user in the `entry` widget (which is a text input field in the GUI), changes this input from a string to a floating-point number using float() , and saves the outcome in a variable called `Chirag`. This transformation is necessary because the `entry.get()` function delivers the input as a string, and in order to execute mathematical operations like doubling, it must be transformed into a numerical data type, such as a float.

4)The next part is the user’s input (Chirag) is multiplied by 2 using this line of code, and the resulting value is stored in a variable called ‘doubled_the_number’. This represents the fundamental operation of doubling the number.

5)The next part gives the result of the Problem, which is the double of the input.

6)The except ValueError: segment serves a crucial role in the function’s error management. It is designed to intercept a ValueError, which arises when the user inputs a value that cannot be transformed into a numerical format, such as letters or special characters. Upon the detection of this error, the code within this block is executed, resulting in the display of a pop-up error notification via messagebox.showerror. This notification features the title “Invalid input” and conveys the message “Please enter another valid number, as it is incorrect,” thereby alerting the user that their entry was not a valid number and encouraging them to make another attempt.

 

root = tk.Tk()
root.title("Project-1")

1. The first line indicates the main window of the application which is initialized by calling tk.Tk(). Tk() in tkinter is a class responsible for creating the primary application window, which serves as the container for all GUI components such as buttons, labels, and entry fields. It is a common practice to use the root variable to reference this main window.
2. The next line sets the title of the application window to ‘Project-1’.

entry_label = tk.Label(root, text="Enter the number to be doubled:")
entry_label.pack(pady=5)

entry = tk.Entry(root)
entry.pack(pady=5)

double_button = tk.Button(root, text="Double", command=double_the_number)
double_button.pack(pady=5)

result_label = tk.Label(root, text="Doubled Number: ")
result_label.pack(pady=20)

The subsequent code snippet is dedicated to generating and structuring the graphical user interface components (widgets) in the main window. It establishes a label (‘entry_label’) to guide the user in entering a number, an entry field (entry) for user input, a button (‘double_button’) that initiates the doubling function upon selection, and a label (‘result_label’) to showcase the doubled number. These widgets are organized within the window utilizing the pack() method, incorporating vertical padding (‘pady’) for adequate spacing.

 

root.mainloop()

The command `root.mainloop()` initiates the primary event loop of the graphical user interface (GUI) application. This loop is crucial as it maintains the application’s operation, remaining in a state of readiness for user interactions, such as clicking buttons or entering text, while simultaneously updating the interface as needed. In the absence of this loop, the application would launch and then promptly terminate, making it vital for ensuring that the window remains open and responsive to user actions.

 

 

User-Input: 45

Output:90.0