app.py

from flask import Flask, request, render_template

app = Flask(__name__)

@app.route('/', methods=['GET', 'POST'])
def calculator():
    if request.method == 'POST':
        try:
            num1 = float(request.form['num1'])
            num2 = float(request.form['num2'])
            operator = request.form['operator']
            
            if operator == 'add':
                result = num1 + num2
            elif operator == 'subtract':
                result = num1 - num2
            elif operator == 'multiply':
                result = num1 * num2
            elif operator == 'divide':
                result = num1 / num2
            
            return render_template('index.html', result=result)
        except ValueError:
            error_message = 'Por favor ingresa números válidos.'
            return render_template('index.html', error=error_message)
    return render_template('index.html')

if __name__ == '__main__':
    app.run(debug=True)