@main.route("/registrer", methods=["GET", "POST"])
def registrer():
    form = RegistrerForm()

    if request.method == "POST":
        if form.validate_on_submit():
            user = User(username=form.username.data,
                        password=form.password.data)
            db.session.add(user)
            db.session.commit()
            return redirect(url_for(".login"))

    return render_template("registrer.html", form=form)