app.py

import streamlit as st
import pandas as pd

# Load dataframe
file = st.file_uploader('Seleccione un archivo: ')
df = file

if file is None:
    pass
else:

    # Sidebar option
    option = st.sidebar.selectbox('Classify results by:', ('Pregunta', 'Categoría'))
    
    # Group dataframe by chosen option
    if option == 'Pregunta':
        grouped_df = df.groupby('Pregunta')
    elif option == 'Categoría':
        grouped_df = df.groupby('Categoría')
    
    # Generate text with bullets
    text = ''
    for name, group in grouped_df:
        text += f'{name}:\n\n'
        for index, row in group.iterrows():
            text += f'- {row["Item"]}\n'
        text += '\n'
    
    # Download link for text file
    st.markdown(f'<a href="data:text/plain;charset=utf-8,{text}" download="result.txt">Download Text File</a>', unsafe_allow_html=True)