app.py

import streamlit as st
import sympy as sp
from forex_python.converter import CurrencyRates, RatesNotAvailableError

# Scientific Calculator Function
def scientific_calculator():
    st.header("Advanced Scientific Calculator")
    expression = st.text_input("Enter the mathematical expression:", value="sin(pi/2) + log(10)")

    if st.button("Calculate"):
        try:
            result = sp.sympify(expression).evalf()
            st.success(f"Result: {result}")
        except Exception as e:
            st.error(f"Invalid Expression! Error: {e}")

# Currency Converter Function
def currency_converter():
    st.header("Currency Converter")
    c = CurrencyRates()

    try:
        # Fetch available currencies
        currencies = list(c.get_rates("").keys())
    except Exception:
        st.error("Unable to fetch currency rates. Using a fallback list.")
        currencies = ["USD", "EUR", "GBP", "INR", "AUD", "CAD"]

    from_currency = st.selectbox("From Currency:", currencies)
    to_currency = st.selectbox("To Currency:", currencies)
    amount = st.number_input("Amount to Convert:", min_value=0.0, value=1.0, step=0.01)

    if st.button("Convert"):
        try:
            converted_amount = c.convert(from_currency, to_currency, amount)
            st.success(f"{amount} {from_currency} = {converted_amount:.2f} {to_currency}")
        except RatesNotAvailableError:
            st.error("Currency rates are currently unavailable.")
        except Exception as e:
            st.error(f"Error in conversion: {e}")

# Main Function to Manage App
def main():
    st.title("Scientific Calculator and Currency Converter")
    st.sidebar.title("Navigation")
    option = st.sidebar.radio("Choose a Tool:", ["Scientific Calculator", "Currency Converter"])

    if option == "Scientific Calculator":
        scientific_calculator()
    elif option == "Currency Converter":
        currency_converter()

if __name__ == "__main__":
    main()