def addcart():
    cur = mysql.connection.cursor()
    if 'uid' not in session:
        noOfItems = 0
    else:
        uid = session['uid']
        cur.execute("SELECT count(id_phone) FROM cart WHERE id_users = " + str(uid))
        noOfItems = cur.fetchall()
    return (noOfItems)


@app.route('/')
def index():
    noOfItems = addcart()
    return render_template("index.html", noOfItems=noOfItems)

<a href="#" class="btn btn-more i-left">
<small><span class="badge badge-primary">{{noOfItems}}</span></small>
</a>