File Upload - Cannot manage csv file after uploaded. about wave

[marek-mihok]

@adrianrjh To use the files uploaded from the browser to the wave server you have to first download it into the wave app. Here is the updated example:

import csv
from h2o_wave import main, app, Q, ui

@app('/')

async def serve(q: Q):
    data_rows = []
    if 'file_upload' in q.args:
        # Since multiple file uploads are allowed, the file_upload argument is a list.
        for path in q.args.file_upload:
            # To use the file uploaded from the browser to the wave server, download it into the app.
            local_path = await q.site.download(path, '.')
            with open(local_path) as csvfile:
                # Do something with the file located at local_path
                # ...
                pass
        # Update the UI
        q.page['example'] = ui.form_card(box='1 1 4 10', items=[
            ui.text(f'file_upload={data_rows}'),
            ui.button(name='show_upload', label='Back', primary=True),
        ])
    else:
        q.page['example'] = ui.form_card(
            box='1 1 4 7',
            items=[
                ui.file_upload(
                    name='file_upload', 
                    label='Upload!', 
                    multiple=True,
                    file_extensions=['csv', 'gz'],
                    max_file_size=10, max_size=15
                )
            ]
        )
    await q.page.save()