I have a Python web application where user upload an image and the code is generating a CSV from that image.

utils.py:

def getCsv(output,im_bgr,im_name, output_dir):

    df1 = pd.DataFrame({"class": class_names)
    coords = ['x_start', 'y_start', 'x_end', 'y_end']
    df2 = pd.DataFrame(data = frac_boxes,  columns = coords) 
    df = pd.concat([df1,df2],axis=1)
    
    # Give the filename you wish to save the file to
    filename = output_dir+im_name.split('.')[0] + '.csv'

    # Use this function to search for any files which match your filename
    files_present = glob.glob(filename)

    # if no matching files, write to csv, if there are matching files, print statement

    if not files_present:
        df.to_csv(filename, index = False)
        
    else:
        print ('WARNING:  File ', filename,  ' already exists!')

app.py:

@app.route('/view_process', endpoint='view_process')
def process_files():
    
    if not session.get('logged_in'):
        return redirect(url_for('login_user'))
    
    subprocess.run(['python', 'utils.py'])  # call the utils.py that generates the csv

    return render_template('view_process.html', message='Files processed successfully')

How to send the generated CSV back to app.py (without saving to computer) and create a link in frontend for user to download it?