Python Program to Make a Simple Calculator: Easy Steps

Creating a Python calculator from the ground level can be easily done with the help of this blog. You’ll learn everything, from setting up your Python environment to crafting arithmetic functions and a user-friendly interface.

Do you want to learn more about Python? Check out our YouTube video to learn more about it!

Why Build a Calculator in Python?

Creating a Python calculator can be a truly satisfying project, and it’s suitable for anyone, whether you’re new to coding or have experience. There are several advantages to taking on this task.

• Building a calculator in Python is a great first project. It provides a practical application for programming abilities and helps in the understanding of Python basics.
• It’s a versatile tool that can help with simple computations as well as serve as a starting point for applications that are more complex.

Setting Up Your Python Environment

It’s important to set up your Python environment for a smooth and effective coding experience. It guarantees that you have the resources and settings in place to create, test, and use Python programs effectively. In addition to making scripting easier, a well-configured environment gives you access to Python’s extensive ecosystem of libraries and modules. This involves the basic yet main two steps:

Python Installation:

Install Python, the programming language that will be used to develop the calculator. Go to the Python official website (python.org), download the installer, and then follow the installation instructions for your operating system.

Choosing a Text Editor or IDE:

Choose an appropriate text editor or Integrated Development Environment (IDE) to develop and run Python code. Visual Studio Code, PyCharm, and Jupyter, Python’s built-in IDE, are all options.

IDEs make coding more efficient by providing tools like code completion, debugging, and project management.

Creating the Calculator Functions

It is important to develop calculator functions because they contain the fundamental reasoning behind carrying out mathematical operations including addition, subtraction, multiplication, and division. These functions act as the calculator’s building blocks, promoting modularity and reuse of the code. 

Addition:

Create a function that takes two numbers as parameters and returns the total of those values.

Example:

def add(x, y):
    return x + y

Subtraction:

Construct a function that processes two numeric inputs, delivering the outcome of their deduction.

Example:

def subtract(x, y):
    return x - y

Multiplication:

Develop a function that takes two numerical inputs and gives the result of their multiplication.

Example:

def multiply(x, y):
    return x * y

Division:

Create a function to accept two numerical arguments and produce the division result.

Example:

def divide(x, y):
    if y == 0:
        return "Cannot divide by zero"
    return x / y

Building the User Interface

Building the user interface is essential because it serves as a bridge between users and your program, improving usability and the user experience. A user-friendly interface makes engagement easier by guiding them through the software’s features.

• Displaying the Menu: 
  • To interact with the user, put up a menu of options.
  • Use print() command to display a menu with options like addition, subtraction, multiplication, division, and exiting the calculator.
• Accepting User Input:
  • Utilize the input() function to record the user’s selection and inputted numbers when accepting user input.
  • In order to utilize the user’s input in calculations, store it in variables.
  • Make sure the user provides you with numeric input.
• Error Handling:
  • Implement error handling to deal with probable problems like division by zero. 
  • This avoids application crashes and offers an approachable response in the event of problems.

Combining the Earlier Steps

Putting It All Together is essential because it combines the earlier processes into a workable method. It establishes the fundamental user interaction and makes your calculator usable in actual situations.

• Creating a Loop:
  • Use a loop (such as a while loop) to enable the calculator to continue working until the user decides to stop it.
  • The menu should be shown iteratively throughout the loop, along with a request for input.
• Calculating Results: 
  • Execute the chosen operation using the provided functions inside the loop.
  • Show the user the outcome.
• Quitting the Calculator:
  • Include a menu item in the calculator’s menu that allows users to quit the calculator when they want to.

Running and Testing Your Calculator

To verify your calculator is accurate and usable, you must run and test it. It enables you to identify any problems and fix them, confirm that the calculator accurately performs arithmetic operations, and increase your confidence in its dependability for regular usage.

• Executing the Python Script: 
  • Use your preferred IDE or the command line to execute the Python script for your calculator.
  • Make sure the code can be executed without a problem.
• Testing Different Operations:
  • Encourage users to test different arithmetic operations to ensure that the calculator is functional.
  • Give illustrations of test scenarios and the expected results for validation.

Python Program to make a Calculator

# Function to add two numbers
def add(x, y):
    return x + y
# Function to subtract two numbers
def subtract(x, y):
    return x - y
# Function to multiply two numbers
def multiply(x, y):
    return x * y
# Function to divide two numbers
def divide(x, y):
    if y == 0:
        return "Cannot divide by zero"
    return x / y
def percentage(x, y):
    if y == 0:
        return "Cannot calculate percentage with denominator as zero"
    return (x / y) * 100
# Main program loop
while True:
    print("Options:")
    print("Enter 'add' for addition")
    print("Enter 'subtract' for subtraction")
    print("Enter 'multiply' for multiplication")
    print("Enter 'divide' for division")
    print("Enter 'percentage' for percentage")
    print("Enter 'quit' to end the program")
    user_input = input(": ")
    if user_input == "quit":
        break
    elif user_input in ["add", "subtract", "multiply", "divide", "percentage"]:
        num1 = float(input("Enter the first number: "))
        num2 = float(input("Enter the second number: "))
        if user_input == "add":
            print("Result: ", add(num1, num2))
        elif user_input == "subtract":
            print("Result: ", subtract(num1, num2))
        elif user_input == "multiply":
            print("Result: ", multiply(num1, num2))
        elif user_input == "divide":
            print("Result: ", divide(num1, num2))
        elif user_input == "percentage":
            print("Result: ", percentage(num1, num2))
    else:
        print("Invalid input")
print("Calculator closed.")

Output:

Wrap-Up

Creating an easy calculator in Python provides a great starting point for those who are new to programming. This step-by-step manual provides users with the critical abilities of function definition, user input management, and error checking. This calculator is useful for everyday computations in addition to being informative. It’s just the start of a programming trip for the learners that can really help you to boost your confidence for creating advance applications for IT industries in the incoming future.