为什么这个变量超出范围？

Question

我想在使用函数后清空函数中的一个全局数组变量，但它显示它正在被隐藏，我不知道为什么。这是我的密码我做错什么了吗

import time
from tkinter import filedialog
import Main

attachments = []


def attach_file():
    filename = filedialog.askopenfilename(initialdir='C:/', title='Select a file')

    attachments.append(filename)
    print(attachments)

    if len(attachments) == 1:
        Main.notif.config(fg="green", text="Attached " + str(len(attachments)) + " file")
    elif len(attachments) > 1:
        Main.notif.config(fg="green", text="Attached " + str(len(attachments)) + " files")

    Main.root.update()
    time.sleep(1)

    Main.notif.config(text="")

    filename2 = attachments[0]
    filetype = filename2.split('.')
    filetype = filetype[1]

    if filetype == "jpg" or filetype == "JPG" or filetype == "png" or filetype == "PNG":
        print("Image")
    else:
        print("doc")

    attachments = [] <= error here

这是用于使用Tkinter、SMTP lib和email.message附加我的Gmail发件人应用程序的文件

Answer 1

a global array variable

您需要告诉Python它是一个全局变量：

def attach_file():
    global attachments # here

    filename = filedialog.askopenfilename(initialdir='C:/', title='Select a file')

    attachments.append(filename)

    # ...

    attachments = [] # no error anymore