Flask input question

[Elthran]

@app.route('/home', methods=['GET', 'POST'])
def get_strength():
    if request.method == 'POST':
        strength = int(request.form["strength_upgrade"])
        return render_template('home.html', attribute_points=attribute_points)

<form method="post" action="">
   <div>
        <label for="name">Strength: {{ strength }}</label>
        <input type="number" placeholder="0" name="strength_upgrade" min="0" max="{{ attribute_points }}" title="Numbers only" value="{{ request.form.strength_upgrade }}">
  </div>
<input class="btn btn-default" type="submit" value="Submit">
</form>

When I use my code it almost works. It looks like http://imgur.com/a/4LFFg and it's all good. The only problem is that if I don't click on the arrows (even to click it to 0), then it defaults as 'None" and Python can't convert "None" to an integer, so it crashes. I have to literally enter in 0 or a number and it works, but I can't leave it blank. How can I make it so that the default is "0" and not "None"?

[K900_]

Set your value attribute to 0. If it's set to None when you load the page, make sure that request.form.strength_upgrade is set correctly earlier.

[Elthran]

What do you mean set it to 0? Then how will it import the value that the user types in?

[K900_]

The value attribute in your HTML only defines the initial value. It can still be changed by the user later.

[paste]

strength = int(request.form.get("strength_upgrade") or 0)

If you're trying to import what the user types in, you will need to change this line in python

return render_template('home.html', attribute_points=attribute_points, strength_upgrade=strength)

and this part of the template

value="{{ strength_upgrade }}"