unregister

@app.route("/unregister", methods=["GET", "POST"])
def unregister():
    if request.method == "GET":
        rows = db.execute("SELECT * FROM registrants")
        return render_template("unregister.html", registrants=rows)
    elif request.method == "POST":
        if request.form["id"]:
            db.execute("DELETE FROM registrants WHERE id = :id", id=request.form["id"])
        return redirect(url_for("registrants"))