download.py

# https://discuss.streamlit.io/t/heres-a-download-function-that-works-for-dataframes-and-txt/4052

import base64

import streamlit as st
import pandas as pd


def download_link(object_to_download, download_filename, download_link_text):
    """
    Generates a link to download the given object_to_download.

    object_to_download (str, pd.DataFrame):  The object to be downloaded.
    download_filename (str): filename and extension of file. e.g. mydata.csv, some_txt_output.txt
    download_link_text (str): Text to display for download link.

    Examples:
    download_link(YOUR_DF, 'YOUR_DF.csv', 'Click here to download data!')
    download_link(YOUR_STRING, 'YOUR_STRING.txt', 'Click here to download your text!')

    """
    if isinstance(object_to_download, pd.DataFrame):
        object_to_download = object_to_download.to_csv(index=False)

    # some strings <-> bytes conversions necessary here
    b64 = base64.b64encode(object_to_download.encode()).decode()

    return f'<a href="data:file/txt;base64,{b64}" download="{download_filename}">{download_link_text}</a>'