python - 关于更新全局变量（python）(about an updating a global variable (python))

Question

x=1
CustomerRef.set(x)

def printBill():
            global x
            filename = tempfile.mktemp (".txt")
            open (filename, "w").write(self.txtReceipt.get('1.0',END))
            open("Bills/"+str(CustomerRef .get()+".txt"),"w").write(self.txtReceipt.get('1.0',END))
            os.startfile(filename,"print")
            x+=1
            CustomerRef.set(x)

This def for the print button is using a billing system.

(打印按钮的此定义正在使用计费系统。)

I want to set the CustomerRefnmber 0 to update as 1 (like first user bill, second user bill like that)and next when the user press the print button that value should have become to 2.

(我想将CustomerRefnmber 0设置为1更新（例如第一个用户帐单，第二个用户帐单），然后在用户按下打印按钮时将值更新为2。)

There is an error in x+=1 line;

(x + = 1行中有错误；)

the error message is: name 'x' is not defined

(错误消息是：未定义名称“ x”)

  ask by kanishka kumarasiri translate from so

Answer 1

等待大神答复