我尝试做一个crud，但当使用插入的按钮发生错误，每次我尝试添加在crud这发生：

Traceback (most recent call last):
      File "C:\Users\mclov\AppData\Local\Programs\Python\Python39\lib\tkinter\__init__.py", line                           1892, in __call__
        return self.func(*args)
      File "C:\Users\mclov\pythonProject1\fluxo.py", line 53, in insertdata
        inserir(lista)
      File "C:\Users\mclov\pythonProject1\lira.py", line 14, in inserir
        cursor = conexao.cursor()
      File "C:\Users\mclov\abadabado\lib\site-packages\mysql\connector\connection_cext.py", line     706,         in cursor
        raise OperationalError("MySQL Connection not available.")
    mysql.connector.errors.OperationalError: MySQL Connection not available.

字符串
代码：

def insertdata():
    tempo = entry_tempo.get()
    evento = entry_descrição.get()
    debito = entry_entrada.get()
    credito = entry_saida.get()
    lista = [tempo, evento, debito, credito]
    if evento == '' or tempo == '' or credito=='' or debito=='':
        messagebox.showerror("campo não pode ser vazio")
    else:
        inserir(lista)
        messagebox.showinfo("todos os dados foram registrados")
        entry_tempo.delete(0, "end")
        entry_descrição.delete(0, "end")
        entry_entrada.delete(0, "end")
        entry_saida.delete(0, "end")
    for widget in frame_tabela.winfo_children():
        widget.destroy()
    showitself()

型