Python code structure with flask integrated

Question

[Newbie] I have written a python program that does some data manipulations to imported xlsx files and save them as csv. It looks kinda like this:

#!/usr/bin/env python2.7    

def main():

    imported_files = import_files_from_input_folder('/input/*.xlsx')

    data_handling_functions(imported_files)

    save_processed_files_to_output_folder('/output/')

if __name__ = '__main__':

    main()

I want to create a web app (using flask) for the users to use the program, by uploading their files to 'input' folder, and then download the results from 'output' folder. Thanks to this topic and some others, I know how to upload multiple files into 'input' folder.

Now, my first question is: how to list all the files in 'output' folder and let users download them?

My second question is: how to wrap/integrate the flask part into the existed program?

score 1 · Accepted Answer · answered Jul 08 '16 at 11:55

This is how a basic Flask web server looks like:

from flask import Flask
app = Flask(__name__)

@app.route("/")
def hello():
    return "Hello World!"

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

so it is quite straightforward to integrate your functionality inside the app. Just add a routing function (like the hello) and call the functions you would normally call inside the main in your code, and after that render the results on a web page, along with some Download buttons. For this you could use the function render_template and give the output (altered in such a way that it can be iterated over to get each file) as a parameter, like so:

@app.route("/")
def hello():
    return render_template('name_of_template', output = your_output)

You can find Flask documentation here and it will show you how to do all that. I recommend that you use the jinja2 API to add Python code to your HTML templates e.g. you could do something like that:

{% for file in output %}
    <!-- Output file inside html tag -->
    <!-- Add a download button -->
{% endfor %}

You can find more about Jinja here

And of course, you would store the CSVs on your server.

Python code structure with flask integrated

1 Answers1