python - Flask end response and continue processing

Question

Is there a way in Flask to send the response to the client and then continue doing some processing? I have a few book-keeping tasks which are to be done, but I don't want to keep the client waiting.

Note that these are actually really fast things I wish to do, thus creating a new thread, or using a queue, isn't really appropriate here. (One of these fast things is actually adding something to a job queue.)

Answer 1

QUICK and EASY method.

We will use pythons Thread Library to acheive this.

Your API consumer has sent something to process and which is processed by my_task() function which takes 10 seconds to execute. But the consumer of the API wants a response as soon as they hit your API which is return_status() function.

You tie the my_task to a thread and then return the quick response to the API consumer, while in the background the big process gets compelete.

Below is a simple POC.

import os
from flask import Flask,jsonify
import time
from threading import Thread

app = Flask(__name__)

@app.route("/")
def main():
    return "Welcome!"

@app.route('/add_')
def return_status():
    """Return first the response and tie the my_task to a thread"""
    Thread(target = my_task).start()
    return jsonify('Response asynchronosly')

def my_task():
    """Big function doing some job here I just put pandas dataframe to csv conversion"""
    time.sleep(10)
    import pandas as pd
    pd.DataFrame(['sameple data']).to_csv('./success.csv')
    return print('large function completed')

if __name__ == "__main__":
    app.run(host="0.0.0.0", port=8080)