Web UI for Python function

Question

I have a python function that takes a series of integers as inputs and returns another series of integers. I\'d like to distribute the function in the form of a web app.

Answer 1

Well it's quite simple really, it's all about how you present a form in html template, getting your view to get the form data, and passing the context back to the template.

I've quickly mocked a sample like what you want (nothing fancy, just back to the basic and show you how these work together), it's only a few lines of code in 2 files main.py (core file, like a view logic) and a template calculation.html:

main.py

from flask import Flask
from flask import render_template
from flask import request

app = Flask(__name__)

@app.route("/", methods=['GET', 'POST'])
def calculation():
    result = 0
    error = ''
    # you may want to customize your GET... in this case not applicable
    if request.method=='POST':
        # get the form data
        first = request.form['first']
        second = request.form['second']
        if first and second:
            try:
                # do your validation or logic here...
                if int(first)>10 or int(first)<1:
                    raise ValueError
                result = int(first) + int(second)
            except ValueError:
                # you may pass custom error message as you like
                error = 'Please input integer from 1-10 only.'
    # you render the template and pass the context result & error
    return render_template('calculation.html', result=result, error=error)

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

templates/calculation.html

<h1>Calculation</h1>
<form method="POST">
    <input type="text" name="first" value="">
    <select name="second">
        <option value="1" selected>1</option>
        <option value="2">2</option>
        <option value="3">3</option>
        <option value="4">4</option>
        <option value="5">5</option>
    </select> 
    <input type="submit" value="Submit">
    {% if result %}
    <p>
        <label name='result'>Answer is: {{ result }}</label>
    </p>
    {% endif %}
    {% if error %}
    <p>
    <label name="error">{{ error }}</label>
    </p>
    {% endif %}
</form>

Hopefully these are self explanatory and you can get to understand how to work with the basic of Flask and forms etc.

Read Flask Doc, and try to follow through, they are quite simple really and once you nail the basic, you may start looking for intermediate and advance topic.

FYI, there is an extension for WTForms called Flask-WTF, it is very handy when dealing with forms, although nothing stops you just doing everything in plain html form like above code.

Hope this helps and I wish you like the simplicity and flexiblity Flask brings you.