Create file dynamically and let the user download it as csv or excel

Dash_download_csv_and_excel.py

import dash
from dash.dependencies import Input, Output

import dash_core_components as dcc
import dash_html_components as html
import pandas as pd
import urllib

import io
import flask

df = pd.DataFrame({
    'a': [1, 2, 3, 4],
    'b': [2, 1, 5, 6],
    'c': ['x', 'x', 'y', 'y']
})

def generate_table(dataframe, max_rows=10):
    return html.Table(
        # Header
        [html.Tr([html.Th(col) for col in dataframe.columns])] +
        # Body
        [html.Tr([
            html.Td(dataframe.iloc[i][col]) for col in dataframe.columns
        ]) for i in range(min(len(dataframe), max_rows))]
    )

app = dash.Dash(__name__)
app.css.append_css({"external_url": "https://codepen.io/chriddyp/pen/bWLwgP.css"})
app.layout = html.Div([
    html.Label('Filter'),

    dcc.Dropdown(
        id='field-dropdown',
        options=[
            {'label': i, 'value': i} for i in
            (['all'] + list(df['c'].unique()))],
        value='all'
    ),
    html.Div(id='table'),
    html.A(html.Button('Export to Excel'),
                        id='download_xlsx'),

    html.A(
        html.Button('Export to CSV'),
        id='download-link',
        download="rawdata.csv",
        href="",
        target="_blank"
    )
])

def filter_data(value):
    if value == 'all':
        return df
    else:
        return df[df['c'] == value]

@app.callback(
    Output('table', 'children'),
    [Input('field-dropdown', 'value')])
def update_table(filter_value):
    dff = filter_data(filter_value)
    return generate_table(dff)

@app.callback(
    Output('download-link', 'href'),
    [Input('field-dropdown', 'value')])
def update_download_link(filter_value):
    dff = filter_data(filter_value)
    csv_string = dff.to_csv(index=False, encoding='utf-8')
    csv_string = "data:text/csv;charset=utf-8," + urllib.parse.quote(csv_string)
    return csv_string

@app.callback(
    Output('download_xlsx', 'href'),
    [Input('field-dropdown', 'value')])
def update_download_link(filter_value):
    return f'/export/excel?option={filter_value}'

@app.server.route('/export/excel')
def export_excel_file():
    option = flask.request.args.get('option')
    option_df = filter_data(option)
    xlsx_io = io.BytesIO()
    writer = pd.ExcelWriter(xlsx_io, engine='xlsxwriter')
    option_df.to_excel(writer, sheet_name='scheme', index=False)
    writer.save()
    xlsx_io.seek(0)

    return flask.send_file(
        xlsx_io,
        mimetype='application/vnd.openxmlformats-officedocument.spreadsheetml.sheet',
        attachment_filename=f'export_{option}.xlsx',
        as_attachment=True,
        cache_timeout=0
    )

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

Hi,

I have a similar code to this (below) to download the csv from Dash and it worked perfectly in Chrome. However, the download doesn't work on Edge / IE. Have you experienced similar issue? Thanks.

@app.callback(
Output('download-link', 'href'),
[Input('field-dropdown', 'value')])
def update_download_link(filter_value):
dff = filter_data(filter_value)
csv_string = dff.to_csv(index=False, encoding='utf-8')
csv_string = "data:text/csv;charset=utf-8," + urllib.parse.quote(csv_string)
return csv_string