app.py

import streamlit as st

def convert_temperature(value, from_unit, to_unit):
    """Convert temperature between Celsius, Fahrenheit, and Kelvin."""
    if from_unit == "Celsius":
        if to_unit == "Fahrenheit":
            return (value * 9/5) + 32
        elif to_unit == "Kelvin":
            return value + 273.15
    elif from_unit == "Fahrenheit":
        if to_unit == "Celsius":
            return (value - 32) * 5/9
        elif to_unit == "Kelvin":
            return (value - 32) * 5/9 + 273.15
    elif from_unit == "Kelvin":
        if to_unit == "Celsius":
            return value - 273.15
        elif to_unit == "Fahrenheit":
            return (value - 273.15) * 9/5 + 32

def main():
    st.title("Temperature Converter")

    # User input: Temperature value
    value = st.number_input("Enter temperature value:", min_value=-273.15)
    
    # User input: Temperature units
    from_unit = st.selectbox("Convert from:", ["Celsius", "Fahrenheit", "Kelvin"])
    to_unit = st.selectbox("Convert to:", ["Celsius", "Fahrenheit", "Kelvin"])

    # Convert and display result
    if from_unit != to_unit:
        converted_value = convert_temperature(value, from_unit, to_unit)
        st.write(f"{value} {from_unit} is equal to {converted_value} {to_unit}.")
    else:
        st.write("Please choose different units to convert.")

if __name__ == "__main__":
    main()