Python GUI登录程序

Question

Me and my friend are making a program that requires a login at the start. We've managed to get the user to input details, and have the program create a text file called (users name) profile with the details in. each one is formatted like this:

(Name)

(Username)

(Password)

when you want to log in, the program asks for your name and finds the file with the name (whatever they typed) profile. if it exists, the program then opens a GUI window and asks for the username and password, and if you put in the correct details for the file it has opened, it says that the details are wrong. We think its to do with the variables, but we've tried lot of different ways of laying it out etc and can't find the problem. Can anyone help? (The code I have included is only the GUI part including the bit that isn't working, the rest is fine.

# Log in
def LogIn():
    name=input("Please enter your name: ")
    file = open(name.lower() + " profile.txt", "r")
#+=========GUI===========GUI============GUI===========+

    #mport modules
    import tkinter
    import time

    #---Window---#
    #make window
    window = tkinter.Tk()
    #change title
    window.title("Python Games Login")
    #change size
    window.geometry("270x210")
    #change window icon
    window.wm_iconbitmap("Login icon.ico")
    #change window colour
    window.configure(bg="#39d972")

    #---Commands---#
    #go
    def callback():
        line = file.readlines()
        username = user.get()
        password = passw.get()
        if username == line[1] and password == line[2]:
            message.configure(text = "Logged in.")
        else:
            message.configure(text = "Username and password don't match the account \n under the name;\n \'" + name + "\'. \nPlease try again.")
    #---Widgets---#
    #labels
    title1 = tkinter.Label(window, text="--Log in to play the Python Games--\n", bg="#39d972")
    usertitle = tkinter.Label(window, text="---Username---", bg="#39d972")
    passtitle = tkinter.Label(window, text="---Password---", bg="#39d972")
    message = tkinter.Label(window, bg="#39d972")

    #text entry windows
    user = tkinter.Entry(window)
    passw = tkinter.Entry(window, show='*')

    #buttons
    go = tkinter.Button(window, text="Log in!", command = callback, bg="#93ff00")

    #pack widgets
    title1.pack()
    usertitle.pack()
    user.pack()
    passtitle.pack()
    passw.pack()
    go.pack()
    message.pack()

    #start window
    window.mainloop()

#+===================GUI END=====================+

Answer 1

I would use python's pickle module to save data. It is much more high level than just saving it in a text file. In my example, I pickled a list of dictionaries.

import pickle
def LogIn():
    name=input("Please enter your name: ").lower()
    #data.pickle should be a list of dictionaries representing a user
    usernames= pickle.load('data.pickle')
    for userdata in usernames:
        if userdata['name']== name:
            return userdata
    #didn't find the name
    print('could not find '+ name+ ' in data.pickle')
    return None

A note about pickle from the docs :

Warning:

The pickle module is not intended to be secure against erroneous or maliciously constructed data. Never unpickle data received from an untrusted or unauthenticated source.

Also check out shelve and marshal , they perform similar results, or consider saving it in a json file format (python has a json module)

Answer 2

Notice that readlines does not strip the end-of-line character(s) from the lines:

In [57]: f = open('data','r')

In [58]: f.readlines()
Out[58]: ['index,value\n', '0,16714217840939775\n', '1,16714217840939776 \n']

So username == line[1] is probably failing since username does not include the end-of-line character. And the same goes for password == line[2] .

A simple fix would be to use

username == line[1].strip()