app.py

import streamlit as st

def calculate(num1, num2, operation):
    if operation == "Add":
        return num1 + num2
    elif operation == "Subtract":
        return num1 - num2
    elif operation == "Multiply":
        return num1 * num2
    elif operation == "Divide":
        if num2 == 0:
            return "Cannot divide by zero!"
        return num1 / num2
    return None

st.title("Simple Calculator")

col1, col2 = st.columns(2)

with col1:
    num1 = st.number_input("Enter first number:", value=0.0)
with col2:
    num2 = st.number_input("Enter second number:", value=0.0)

operation = st.selectbox(
    "Select operation:",
    ["Add", "Subtract", "Multiply", "Divide"]
)

if st.button("Calculate"):
    result = calculate(num1, num2, operation)
    st.subheader(f"Result: {result}")