Python如何将用户提供的IP地址写入文件？

Question

so here's the problem. I have started using python for a little while and I have come across a problem. Although it may seem basic at first, it has had me busy for hours on end. *I do not receive any syntax errors when running the program, although the program fails to write the new IP to file.

I am making a function for a program, that asks the client for a new IP address as the servers(my IP) is currently not static. As my IP changes quite frequently, i would like to give clients (that are attempting to establish a connection with me) the option to change the IP that they are trying to connect to.

So here is the function:

#CONFIGURE NEW IP
def IpConfigNew():
   #Creates new window 
   IpConfig = Tk()
   IpConfig.configure(background = 'white')
   IpConfig.title('Configure IP')
   IpConfig.geometry('300x60+260+380')
   IpNew = StringVar()
   Label(IpConfig, font  = ('Helvetica',12), text = 'Please enter the IP address of the   server', bg = 'white').place(x=0,y=4)
   #Creates box for user to type IP in.
   Entry(IpConfig,textvariable=IpNew, bg = "light blue").place(x=4,y=35)

 #Store New Ip NOTE that it is nested within IpConfigNew
 def IpStore():
     #Retrieves new IP from text box and stores it in variable 
     GetIpNew = IpNew.get()
     mypath = str('Latest Server')
     #Creates directory to write new IP to.
     if not os.path.isdir(mypath):
         os.makedirs(mypath)
     StoreLatestServer = open('Latest Server\NewIp.txt', 'w')
     #Writes new IP
     StoreLatestServer.write("%s"%(GetIpNew))
     StoreLatestServer.close()
     IpConfig.destroy()#Closes window

   #Calls on function IpStore in order to store the new IP    
   Button(IpConfig,text = 'Done', command = IpStore).place(x=150,y=30)
   IpConfig.mainloop()

def PromptIpReconfig():
  confirm = tkMessageBox.askyesno(title = "Configure Server IP", message = "Are you   sure?")
#Checks to see if the user chose to change IP
if confirm >0: 
  #In the event that the user said yes go to IpConfigNew
  IpConfigNew()
else:
   return

#Configure Menu Bar #Sets up Menu Bar for parent Window(app)
menubar = Menu(app)
filemenu = Menu(menubar,tearoff = 0)
# Goes to     PromptIpReconfig (Prompts user to Reconfigure the IP after clicking button)
filemenu.add_command(label="Configure IP", command = PromptIpReconfig) 
filemenu.add_command(label="Quit", command=app.destroy)
menubar.add_cascade(label='Options',menu = filemenu)
app.config(menu=menubar)#Draws menubar on parent window(app)

I am not sure why its not working as I have done this before expect slightly differently. When I attempt to write the new IP to file, nothing gets written to the file. The new directory is created, so I know that the function is working. I contrasted between the program that I made a while back that work and this one. What i found was that if I did this it worked fine:

#CONFIGURE NEW IP
#Creates new window
IpConfig = Tk()
IpConfig.configure(background = 'white')
IpConfig.title('Configure IP')
IpConfig.geometry('300x60+260+380')
IpNew = StringVar()
Label(IpConfig, font  = ('Helvetica',12), text = 'Please enter the IP address of the   server', bg = 'white').place(x=0,y=4)
#Creates box for user to type IP in.
Entry(IpConfig,textvariable=IpNew, bg = "light blue").place(x=4,y=35)

 #Store New Ip
 def IpStore():
     #Retrieves new IP from text box and stores it in variable GetIpNew
     GetIpNew = IpNew.get()
     mypath = str('Latest Server')
     #Creates directory to write new IP to.
     if not os.path.isdir(mypath):
         os.makedirs(mypath)
     StoreLatestServer = open('Latest Server\NewIp.txt', 'w')
     #Writes new IP
     StoreLatestServer.write("%s"%(GetIpNew))
     StoreLatestServer.close()
     #Closes window
     IpConfig.destroy()

#Calls on function IpStore in order to store the new IP
Button(IpConfig,text = 'Done', command = IpStore).place(x=150,y=30)
IpConfig.mainloop()

I found that if I initiate without using the menu bar and instead just initiate it at program start, it works fine. I am not sure whether the problem is calling the IpConfigNew function from the menu bar or whether it has something to do with the fact that I am nesting functions.

I would love it if someone could help me out here as its been bugging me for days!

Answer 1

I would move those 2 lines inside IpConfigNew , at the end:

#Calls on function IpStore in order to store the new IP    
Button(IpConfig,text = 'Done', command = IpStore).place(x=150,y=30)
IpConfig.mainloop()

EDIT : it seems there is a kind of bug with multiple event loops and StringVar, see Tkinter Folklore . Anyway in your case you want to show a dialog, you don't need another Tk loop. So change your code like this:

def IpConfigNew():
    #Creates a Toplevel window instead of a new "main" window in a new loop
    IpConfig = Toplevel(app) 

    ...

    #IpConfig.mainloop()
    app.wait_window(IpConfig)

This solves your problem in my test.

Answer 2

I didnt make the layout of my program very clear beforehand, I will try and explain it now.

What i have is my main window and inside my main window(called "app") i have set up a menu bar. This menu bar has aa cascade called "options" and a command called "PromptIpReconfig":

app = Tk() 
filemenu.add_command(label="Configure IP", command = PromptIpReconfig)
filemenu.add_command(label="Quit", command=app.destroy)
menubar.add_cascade(label='Options',menu = filemenu)

When I call the function "PromptIpReconfig" the following happens:

def PromptIpReconfig():
   confirm = tkMessageBox.askyesno(title = "Configure Server IP", message = "Are you sure?")
   if confirm >0:
      IpConfigNew()
   else:
      return

If the user decides to say yes then IpConfigNew() is called:

#CONFIGURE NEW IP
def IpConfigNew():
    IpConfig = Tk()
    IpConfig.configure(background = 'white')
    IpConfig.title('Configure IP')
    IpConfig.geometry('300x60+260+380')
    IpNew = StringVar()
    Label(IpConfig, font  = ('Helvetica',12), text = 'Please enter the IP address of the server', bg = 'white').place(x=0,y=4)
    Entry(IpConfig,textvariable=IpNew, bg = "light blue").place(x=4,y=35)

    #Store New Ip
    def IpStore():
        GetIpNew = IpNew.get()
        mypath = str('Latest Server')
        if not os.path.isdir(mypath):
            os.makedirs(mypath)
        StoreLatestServer = open('Latest Server\NewIp.txt', 'w')
        StoreLatestServer.write("%s"%(GetIpNew))
        StoreLatestServer.close()
        IpConfig.destroy()

    Button(IpConfig,text = 'Done', command = IpStore).place(x=150,y=30)
    IpConfig.mainloop()

IpConfigNew opens a child window IpConfig = Tk() within the main window. The child window provides a button to click after the new IP has been entered. Once the button is clicked it calls the command "IpStore":

#Store New Ip
def IpStore():
    GetIpNew = IpNew.get()
    mypath = str('Latest Server')
    if not os.path.isdir(mypath):
        os.makedirs(mypath)
    StoreLatestServer = open('Latest Server\NewIp.txt', 'w')
    StoreLatestServer.write("%s"%(GetIpNew))
    StoreLatestServer.close()
    IpConfig.destroy()

So basically the overall layout of my program looks like this:

from Tkinter import *
import os
import tkMessageBox
#Create parent window
app = Tk()

def IpConfigNew():
   #Creates new window 
   IpConfig = Tk()
   IpNew = StringVar()
   Label(IpConfig, font  = ('Helvetica',12), text = 'Please enter the IP address of the   server', bg = 'white').place(x=0,y=4)
   #Creates box for user to type IP in.
   Entry(IpConfig,textvariable=IpNew, bg = "light blue").place(x=4,y=35)

 #Store New Ip NOTE that it is nested within IpConfigNew
 def IpStore():
     #Retrieves new IP from text box and stores it in variable 
     GetIpNew = IpNew.get()
     mypath = str('Latest Server')
     #Creates directory to write new IP to.
     if not os.path.isdir(mypath):
         os.makedirs(mypath)
     StoreLatestServer = open('Latest Server\NewIp.txt', 'w')
     #Writes new IP
     StoreLatestServer.write("%s"%(GetIpNew))
     StoreLatestServer.close()
     IpConfig.destroy()#Closes window

   #Calls on function IpStore in order to store the new IP    
   Button(IpConfig,text = 'Done', command = IpStore).place(x=150,y=30)
   IpConfig.mainloop()

def PromptIpReconfig():
   confirm = tkMessageBox.askyesno(title = "Configure Server IP", message = "Are you sure?")
   if confirm >0:
      #In the case that the user says yes
      IpConfigNew()
   else:
      return


#Create menu bar
filemenu.add_command(label="Configure IP", command = PromptIpReconfig)
filemenu.add_command(label="Quit", command=app.destroy)
menubar.add_cascade(label='Options',menu = filemenu)

app.mainloop()

I am pretty sure the problem is the function IpConfigNew as this seems to work:

from Tkinter import *
import tkMessageBox
import os


#Creates new window   
IpConfig = Tk()
IpNew = StringVar()
Label(IpConfig, font  = ('Helvetica',12), text = 'Please enter the IP address of the   server', bg = 'white').place(x=0,y=4)
#Creates box for user to type IP in.
Entry(IpConfig,textvariable=IpNew, bg = "light blue").place(x=4,y=35)

#Store New Ip NOTE that it is nested within IpConfigNew
def IpStore():
     #Retrieves new IP from text box and stores it in variable 
     GetIpNew = IpNew.get()
     mypath = str('Latest Server')
     #Creates directory to write new IP to.
     if not os.path.isdir(mypath):
         os.makedirs(mypath)
     StoreLatestServer = open('Latest Server\NewIp.txt', 'w')
     #Writes new IP
     StoreLatestServer.write("%s"%(GetIpNew))
     StoreLatestServer.close()
     IpConfig.destroy()#Closes window

#Calls on function IpStore in order to store the new IP    
Button(IpConfig,text = 'Done', command = IpStore).place(x=150,y=30)
IpConfig.mainloop()

This should give you guys a much clearer understanding of what I am dealing with. Thanks