python如何更改全局变量

我想得到上传成功的某种确认，我的方法定义如下。然而，全局变量的值并没有改变。请帮忙

global upload_confirm
upload_confirm = False

def confirm_upload():
    upload_confirm = True

def start_new_upload():
    confirm_upload()
    while (upload_confirm != True):
        print "waiting for upload to be true"
        time.sleep(5)
    if (upload_confirm == True):
        print "start Upload"

start_new_upload()

你可以试试这个：

def confirm_upload():
    global upload_confirm
    upload_confirm = True

---

由于您在局部范围内执行

upload\u confirm=True

，Python将其视为局部变量。因此，您的全局变量保持不变。

您需要将

global

语句放在要访问全局变量的范围内，即：

upload_confirm = False

def confirm_upload():
    global upload_confirm
    upload_confirm = True

---

global

语句应位于函数内部

def confirm_upload():
    global upload_confirm
    upload_confirm = True

---

否则，

upload\u confirm=..

将创建一个局部变量。

在

confirm\u upload（）

方法中尝试此操作

def confirm_upload():
    global upload_confirm #Add this line
    upload_confirm = True

---

您需要在方法内部将其声明为全局，否则它将默认为局部。

如果我只想读取全局变量，是否可以跳过每个函数开头的

global

声明？