title: Send multiple return values from python to react when posting data
body: <p>Let's say I have a post request like this:</p>
  
  <pre><code>addPerson() {
      axios.post("http://127.0.0.1:5000/addPerson", {personArray})
        .then(res =&gt; {
           console.log("Persons added")
        })
    }
  </code></pre>
  
  <p>So I'm passing a list of persons to python and want to add those persons to the database.
  This is for example the python code:</p>
  
  <pre><code>@app.route("/addPerson", methods=["POST"])
  def addPersonMethod():
  
      personArray = request.json.get('personArray')
  
      for person in personArray:
            ....code that adds a person to the database....
  
             return a value to the frontend after a person has been added
  
      return "All persons added"
  </code></pre>
  
  <p>Now I wanna let the user know how many persons have been added so that I can display something like "4 of 1400 persons have been added" in the frontend and update the number of added persons every time a new person gets added to the database (so after every iteration of the for loop). This is important for my programm because it could take very long if e.g. 100.000 persons should be added. Because it could take very long, the user should see how long it could take to upload all persons to the database.</p>
  
  <p>Is there a way to return for example an integer value to the frontend after every iteration of the for loop?</p>