It can't handle while loop if I enter a wrong password in tkinter

Question

from tkinter import *
from PIL import Image,ImageTk
import os

    
def login_success():
    global success_win
    success_win = Tk()
    success_win.title('Welcome')
    success_label = Label(success_win,text='You logged in successfully')
    success_label.pack(pady=10)
    exitbtn = Button(success_win,text='OK',command=success_win.destroy)
    exitbtn.pack(pady=10)

def forget_password():
    global forwin
    forwin = Tk()
    forwin.title('Verification')

    Verify_label = Label(forwin,text='Put your phone number',fg='red')
    Verify_label.pack(pady=10)
    phone_no = IntVar()
    Verify_entry = Entry(forwin,width=20,textvariable=phone_no)
    Verify_entry.pack(pady=10)
    Submit_btn = Button(forwin,text='Submit',command=reset_pw)
    Submit_btn.pack(pady=10)

def reset_pw():
    Label(forwin,text='The code has been sent to your mobile').pack()
    Button(forwin,text='Login',command=login).pack()
    
    
def login_verify():
    username1 = user_login_entry.get()
    password1 = pw_login_entry.get()
    pw_login_entry.delete(0,END)

    list_of_files = os.listdir()
    username_file = username1+'.txt'

    if username_file in list_of_files:
        times_left = 5
        right_input = False
        file1 = open(username_file)
        verify = file1.read().splitlines()
        while not right_input:
            if password1 in verify:
                login_success()
                right_input = True
            elif times_left == 0:
                reset_pw()
            else:
                Label(logwin,text='Try again',fg='red').pack()
                times_left -= 1
                    
    else:
        Label(logwin,text='No current user',fg='red').pack()

    

My aim is to let the wrong password users try five times before go to reset password and when I run the program I enter a wrong password it shows five times at the first time rather than going once each time. May I ask where is the problem? Can tkinter handle one by one using while loop? Any methods that can handle looping but not going all times at the first time?

Answer 1

Try to avoid any infinit loops except the mainloop of tkinter. One will interrupt the other and your program freezes till they are done.

Multiple if-statements and tk.Variables will do this job as well.

import tkinter as tk
import os

def login_verify():
    #get your input
    username1 = _uv.get()
    password1 = _pw.get()
    user_lst = os.listdir()
    user = username1+'.txt'
    #ask for user
    user_verify = verify_user(user,user_lst)
    if user_verify: #if user is known
        #ask for password
        pw_verify = verify_password(user,user_lst, password1)
        if pw_verify: #password is correct
            u_n.delete(0,'end')
            p_w.delete(0,'end')
        else: #wrong password
            p_w.delete(0,'end')
    else: #user isnt known
        display.configure(text='User not found')
        u_n.delete(0,'end')

def verify_user(user, lst):
    if user in lst:
        print('User in register')
        return True
    else:
        print('User isnt known yet, sign in.')
        return False

def verify_password(user,user_lst, pw):
    user_f = open(user)
    verify = user_f.read().splitlines()
    times_left = _pwc.get() #check if there are trys left
    if times_left >=1:
        if pw in verify:
            print('login_success()')
            _pwc.set(5) #get another 5 trys after success
            return True
        else:
            display.configure(text='wrong password')
            _pwc.set(times_left-1) #minus 1 try
            print(_pwc.get())
            return False
    else:
        print('reset_pw()')
        

root = tk.Tk()


_uv = tk.StringVar()
_pw = tk.StringVar()

_pwc = tk.IntVar() #keep track of trys
_pwc.set(5) #set default 

display = tk.Label(text='please sign in') #communicate with user
u_n = tk.Entry(root, textvariable=_uv)
p_w = tk.Entry(root, textvariable=_pw)
b = tk.Button(root, text='verify', command=login_verify)

display.grid(column=0,row=0,columnspan=2)
u_n.grid(column=0,row=1)
p_w.grid(column=1, row=1)
b.grid(column=0, row=2,columnspan=2)

root.mainloop()