Simple Calculator Program in Python with tkinter
The rest of the code 1
The rest of the code 2
Output:
Explanation:
Imports:
tkinter as tk: Imports the tkinter module under the alias tk.
from tkinter import messagebox: Imports the messagebox submodule from tkinter to show error messages.
Functions:
evaluate_expression(): Attempts to evaluate the expression entered in the entry widget (entry). It uses Python's eval() function to evaluate the string expression to a numerical result. If successful, it clears the entry and inserts the result. If there's an error (e.g., invalid input), it shows an error message using messagebox.showerror().add_to_expression(char): Appends the character char (which represents a button's text) to the end of the entry widget (entry).clear_expression(): Clears the content of the entry widget (entry).
Creating the Main Window (root):
tk.Tk(): Creates the main window of the application.root.title("Simple Calculator"): Sets the title of the window to "Simple Calculator".
Entry Widget:
tk.Entry(root, width=30, borderwidth=5): Creates an entry widget (entry) within the main window (root) for displaying and entering expressions.entry.grid(row=0, column=0, columnspan=4, padx=10, pady=10): Places the entry widget in the first row, spanning all four columns with padding around it.
Buttons:
- Defined as a list of tuples (
buttons) where each tuple contains the text to display on the button, its row position, and column position.
- Buttons are created using a loop (
for (text, row, col) in buttons), where each button is placed in its respective row and column using tk.Button().
Clear (C) and Evaluate (=) Buttons:
tk.Button(root, text='C', width=7, height=3, command=clear_expression): Creates a button labeled "C" that clears the entry when clicked (command=clear_expression).tk.Button(root, text='=', width=7, height=3, command=evaluate_expression): Creates a button labeled "=" that evaluates the expression and displays the result when clicked (command=evaluate_expression).
Main Loop:
evaluate_expression(): Attempts to evaluate the expression entered in the entry widget (entry). It uses Python's eval() function to evaluate the string expression to a numerical result. If successful, it clears the entry and inserts the result. If there's an error (e.g., invalid input), it shows an error message using messagebox.showerror().add_to_expression(char): Appends the character char (which represents a button's text) to the end of the entry widget (entry).clear_expression(): Clears the content of the entry widget (entry).tk.Tk():Creates the main window of the application.root.title("Simple Calculator"):Sets the title of the window to "Simple Calculator".
Entry Widget:
tk.Entry(root, width=30, borderwidth=5): Creates an entry widget (entry) within the main window (root) for displaying and entering expressions.entry.grid(row=0, column=0, columnspan=4, padx=10, pady=10): Places the entry widget in the first row, spanning all four columns with padding around it.
Buttons:
- Defined as a list of tuples (
buttons) where each tuple contains the text to display on the button, its row position, and column position.
- Buttons are created using a loop (
for (text, row, col) in buttons), where each button is placed in its respective row and column using tk.Button().
Clear (C) and Evaluate (=) Buttons:
tk.Button(root, text='C', width=7, height=3, command=clear_expression): Creates a button labeled "C" that clears the entry when clicked (command=clear_expression).tk.Button(root, text='=', width=7, height=3, command=evaluate_expression): Creates a button labeled "=" that evaluates the expression and displays the result when clicked (command=evaluate_expression).
Main Loop:
tk.Entry(root, width=30, borderwidth=5): Creates an entry widget (entry) within the main window (root) for displaying and entering expressions.entry.grid(row=0, column=0, columnspan=4, padx=10, pady=10): Places the entry widget in the first row, spanning all four columns with padding around it.- Defined as a list of tuples (
buttons) where each tuple contains the text to display on the button, its row position, and column position. - Buttons are created using a loop (
for (text, row, col) in buttons), where each button is placed in its respective row and column usingtk.Button().
Clear (C) and Evaluate (=) Buttons:
tk.Button(root, text='C', width=7, height=3, command=clear_expression): Creates a button labeled "C" that clears the entry when clicked (command=clear_expression).tk.Button(root, text='=', width=7, height=3, command=evaluate_expression): Creates a button labeled "=" that evaluates the expression and displays the result when clicked (command=evaluate_expression).
Main Loop:
tk.Button(root, text='C', width=7, height=3, command=clear_expression): Creates a button labeled "C" that clears the entry when clicked (command=clear_expression).tk.Button(root, text='=', width=7, height=3, command=evaluate_expression): Creates a button labeled "=" that evaluates the expression and displays the result when clicked (command=evaluate_expression).root.mainloop(): Starts the main event loop of the tkinter application, which listens for events (such as button clicks) and handles them.