Flask: Download a csv file on clicking a button

Here is one way to download a CSV file with no Javascript:

#!/usr/bin/python

from flask import Flask, Response
app = Flask(__name__)

@app.route("/")
def hello():
    return '''
        <html><body>
        Hello. <a href="/getPlotCSV">Click me.</a>
        </body></html>
        '''

@app.route("/getPlotCSV")
def getPlotCSV():
    # with open("outputs/Adjacency.csv") as fp:
    #     csv = fp.read()
    csv = '1,2,3\n4,5,6\n'
    return Response(
        csv,
        mimetype="text/csv",
        headers={"Content-disposition":
                 "attachment; filename=myplot.csv"})


app.run(debug=True)

You can use flask.send_file() to send a static file:

from flask import send_file

@app.route('/getPlotCSV') # this is a job for GET, not POST
def plot_csv():
    return send_file(
        'outputs/Adjacency.csv',
        mimetype='text/csv',
        download_name='Adjacency.csv',
        as_attachment=True
    )

Prior to Flask 2.0, download_name was called attachment_filename.

Tags:

Python

Javascript

Csv

Json

Flask

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