Validating valid input in Python/Flask?

R

realgord882015-02-02 00:10:30

Flask

realgord88, 2015-02-02 00:10:30

Help me write a program that will check the correctness of the entered answer to a mathematical expression, but with the main condition - sessions. Now the non-working code is:

def index():
    form = NameForm()
    first = random.randint(0,10)
    second = random.randint(0,10)
    answer = first * second
    if form.validate_on_submit():
        if answer == int(form.ans.data):
            flash('Right')
        return redirect(url_for('index'))

C me buns ;)

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3 answer(s)

T

throughtheether, 2015-02-02
@realgord88

Help write a program that will check the correctness of the entered answer to a mathematical expression,

More or less like this. You show the user (when receiving a GET request) two numbers. On the form, in addition, there must be two hidden input fields with the same numbers. Anti-forgery protection (so that the user adds exactly the numbers that were sent to him) can be implemented using a csrf token or self-hashing of two values (the first option is preferable). When receiving a POST request, compare the sum of numbers (from hidden fields) with user input and draw conclusions.
validate.py:

from flask import Flask, render_template, request
from wtforms import TextField, HiddenField
from flask.ext.wtf import Form
from random import randint
app = Flask(__name__)
app.secret_key = 'perkele 9000'

class TestForm(Form):
    answer = TextField("answer")
    val1 = HiddenField("val1")
    val2 = HiddenField("val2")


@app.route('/', methods=["POST", "GET"])
def test():
    if request.method == 'POST':
        form = TestForm(request.form)
        try:
            if int(form.val1.data) + int(form.val2.data) == int(form.answer.data):
                return "OK!"
        except ValueError:
            pass
        return "Not OK!"

    if request.method == 'GET':
        form = TestForm()
        form.val1.data = randint(1,99)
        form.val2.data = randint(1,99)
        return render_template('template.html', form = form)

if __name__ == '__main__':
    app.debug = True
    app.run()

templates/template.html:

<html>
<head>
        <title>Test your arithmetic skills</title>
</head>
<body>
<table>
    <tr><td>Calculate <b>{{form.val1.data}} + {{form.val2.data}}</b></td></tr>
    <tr>
    <td>
    <form method=post action="{{ url_for('test') }}">
        {% for field in form %}
            {{field}}
        {% endfor %}
        <input type=submit value="OK">
    </form>
    </td>
    </tr>
</table>
</body>
</html>

Only an outline is shown here, as an extension of the theme, you can use an IntegerField for the user input field, and also implement a specific form validator.

D

DevMan, 2017-09-03
@lemonlimelike

yes, my friend, you still need to learn and learn.
https://jsfiddle.net/b9pdaqsd/

E

Ernest Fayzullin, 2017-09-03
@ernesto77

advice

$view_2 = isset($_GET['view_2']) ? @intval($_GET['view_2']) : null;

if (!$view_2)
    return false;

...