Step-by-Step Guide: Building a Simple Calculator with Streamlit

In this guide, we'll walk through the process of building a basic calculator application using Python and Streamlit. Streamlit is a powerful library for building interactive web applications with minimal code. Let's get started!

Step 1: Setting Up Your Environment

Make sure you have Python installed on your system. You can download it from python.org.
Install Streamlit using pip:
```
pip install streamlit
```

alternative: streamlit sandbox

Step 2: Creating the Project Structure

Create a new directory for your project:

mkdir simple-calculator
cd simple-calculator

Inside the project directory, create a new Python script for the calculator application. Let's name it calculator.py.

Step 3: Writing the Calculator Code

Open calculator.py in your favorite text editor or IDE.
Import the necessary libraries:
```
import streamlit as st
```
Define the Streamlit app layout:
```
st.title('Simple Calculator')
```

Add input fields for numbers and operators:

num1 = st.number_input('Enter the first number:')
operator = st.selectbox('Select operator:', ['+', '-'])
num2 = st.number_input('Enter the second number:')

Add a button to perform the calculation:

if st.button('Calculate'):
    result = None
    if operator == '+':
        result = num1 + num2
    elif operator == '-':
        result = num1 - num2
    
    st.write(f'Result: {result}')

Step 4: Running the Application

Save your changes to calculator.py.
Open your terminal and navigate to the project directory (simple-calculator).
Run the Streamlit application:

streamlit run calculator.py

Once the application is running, open your web browser and navigate to the provided URL (usually http://localhost:8501).

Step 5: Adding Subtraction, Multiplication, and Division (Tasks)

Task 1: Multiplication: Implement the multiplication functionality by adding a conditional block for the * operator.
Task 2: Division: Implement the division functionality by adding a conditional block for the / operator. Make sure to handle division by zero error.

Step 6: Testing the Application

Use the input fields and buttons to perform calculations. Enter numbers and select operators to build your expression, and click the "Calculate" button to see the result.
Test different scenarios to ensure the calculator behaves as expected.

Step 7: Customization and Enhancements

Feel free to customize the layout and styling of the calculator application using Streamlit's features.
You can add more advanced features or functionalities to the calculator based on your requirements and preferences.
Explore Streamlit's documentation for more ideas and possibilities.

Congratulations! You've successfully built a simple calculator application using Python and Streamlit.

edocm/simple-calculator