Calculator Application

This project is a command-line-based Calculator Application implemented in Python. It provides basic arithmetic operations along with a persistent history feature, making it convenient for users to review past calculations or manage their history.

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Features

1. Basic Arithmetic Operations

   • Addition (+)
   • Subtraction (-)
   • Multiplication (*)
   • Division (/)

2. Persistent History

   • All calculations are stored in a history.txt file for future reference.

3. History Management

   • View history.
   • Clear history.

4. Command Interface

   • Interactive and easy-to-use terminal interface with multiple commands.

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How to Use

Commands Overview

Upon running the application, you will see the available commands:

Command	Description
0	Exit the program
1	Perform addition
2	Perform subtraction
3	Perform multiplication
4	Perform division
5	Show calculation history
6	Clear calculation history
7	Display the main menu again

Running the Application

1. Launch the program by running the script:

   python <filename>.py

2. Follow the prompts to input commands and perform calculations.

Example Workflow

1. Select a command (e.g., 1 for addition).
2. Input the two numbers for the operation when prompted.
3. View the result.
4. Check the history (5) or perform another operation.

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File Structure

• history.txt: A file created automatically to store calculation history.
  • Each entry is stored in the format: <number1>;<operator>;<number2>;<result>.

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Example Usage

Initial Menu

Calculator
0 calculations stored in history
Commands:
0 - end program
1 - calculate addition (+)
2 - calculate subtraction (-)
3 - calculate multiplication (*)
4 - calculate division (/)
5 - show history
6 - empty history
7 - show commands

Performing Addition

Select command: 1
Input number: 5
Input number: 3
Result: 8.0

Viewing History

Select command: 5
1 calculations in history:
5.0;+;3.0;8.0

Clearing History

Select command: 6
History cleared.

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Future Enhancements

• Add support for more advanced operations (e.g., square root, exponentiation).
• Implement input validation to handle invalid or non-numeric inputs gracefully.
• Introduce a graphical user interface (GUI) for better user experience.
• Allow history export to external files (e.g., CSV or JSON).

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How to Contribute

Feel free to fork this repository and submit pull requests to improve functionality or fix any issues.

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Author

This Calculator Application was created to demonstrate the use of Python for simple command-line tools with file I/O capabilities. Enjoy using it for your calculations!