from flask import Flask, send_file
import requests
import io

app = Flask(__name__)

@app.route('/')
def index():
    # get file from other page
    response = requests.get('https://github.com/furas/mate-python-applets/archive/master.zip')

    # create file in memory
    zip_content = io.BytesIO(response.content)

    # send it to client - it needs `as_attachment` to change name with `attachment_filename`
    return send_file(zip_content, mimetype='application/zip', as_attachment=True, attachment_filename='archive.zip')

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