报错 cursor() takes 1 positional argument but 2 were

def selectRecord(request):

    #cursor = conn.cursor()  

    cursor = conn.cursor(pymysql.cursors.DictCursor)

    cursor.execute('select * from book ', [])

    books = cursor.fetchall()

    conn.close()

    return HttpResponse(books)

这段代码用conn.cursor()  可以正常执行

用 cursor = conn.cursor(pymysql.cursors.DictCursor)

报错 cursor() takes 1 positional argument but 2 were given

这是为什么？