Banking System Project

import tkinter as tk
import random

class MainWindow(tk.Frame):

    def __init__(self, master=None):
        #master constructor
        super().__init__(master)
        self.grid(columnspan=2)
        #call the creation of all UI items used
        self.create_widgets()

    def create_widgets(self):
        #Widget creation, all GUI related items defined here
        #Banner
        self.banner = tk.Label(self, text="WELCOME TO THE BANKING SYSTEM")
        self.banner.grid(row=0, columnspan=2, padx=5, pady=10)
        #Buttons
        self.loginBtn = tk.Button(self, text="Login with existing account", command=self.loginForm)
        self.loginBtn.grid(row=1, column=0, padx=5)
        self.createBtn = tk.Button(self, text="Setup an account", command=self.registerForm)
        self.createBtn.grid(row=1, column=1, padx=5)
        self.quitBtn = tk.Button(self, text="QUIT", fg="red", command=root.destroy)
        self.quitBtn.grid(row=2, column=0, columnspan=2, pady=20)
        #user widgets
        self.usernameLabel = tk.Label(self, text="Username:")
        self.usernameEntry = tk.Entry(self)
        self.passwordLabel = tk.Label(self, text="Password:")
        self.passwordEntry = tk.Entry(self, show="*")
        self.hiddenPhraseLabel = tk.Label(self, text="Hidden phrase:")
        self.hiddenPhraseEntry = tk.Entry(self)
        #
        self.doLoginBtn = tk.Button(self, text="Login", command=self.login)
        self.doRegisterBtn = tk.Button(self, text="Register", command=self.register)
        self.warningLabel = tk.Label(self, fg="red")
        self.confirmPhraseLabel = tk.Label(self, fg="blue")
        self.confirmPhraseBtn = tk.Button(self, text="Confirm phrase")

    def login(self):
        #clear previous warning messages (if any)
        self.clearWarnings()
        #get input values from the username and password fields
        username = self.usernameEntry.get()
        password = self.passwordEntry.get()
        #check if user exists in the text file
        userData = self.findUserData(username)
        if userData:
            #Check if given password matches the stored password
            if userData[1]==password:
                #Show the hidden phrase challenge (last step of login)
                self.hiddenPhraseLabel.grid(row=5, column=0, padx=10)
                self.hiddenPhraseEntry.grid(row=5, column=1, padx=10)
                self.doLoginBtn.grid_forget()
                #Get the random positions to ask the user from the phrase
                challengeIndexes = self.getPhraseChallenge()
                challengeText = "Enter the characters number\n" + str(challengeIndexes[0]+1)
                challengeText += ", " + str(challengeIndexes[1]+1) + " and " + str(challengeIndexes[2]+1)
                challengeText += " from your hidden phrase.\n (comma separated)"
                #show the hidden phrase challenge
                self.confirmPhraseLabel["text"]=challengeText
                self.confirmPhraseLabel.grid(row=8, column=0)
                self.confirmPhraseBtn["command"] = lambda: self.confirmPhrase(userData[2], challengeIndexes)
                self.confirmPhraseBtn.grid(row=8, column=1)
            else:
                #If the password doesn't match, show an alert
                self.warningLabel["text"]="The password is incorrect"
                self.warningLabel.grid(row=7, columnspan=2)
        else:
            #If the user does not exists in the file,  show an alert
            self.warningLabel["text"]="Username not found"
            self.warningLabel.grid(row=7, columnspan=2)

    def confirmPhrase(self, hiddenPhrase, indexes):
        #Get the text from user input
        confirmText = self.hiddenPhraseEntry.get()
        #Construct how the user input should look using the random indexes
        challengeText = hiddenPhrase[indexes[0]] + "," + hiddenPhrase[indexes[1]] + "," + hiddenPhrase[indexes[2]]
        if confirmText == challengeText:
            #If the texts match, complete login
            self.cleanWidgets()
            self.warningLabel["text"]="Login Successful!\nWelcome"
            self.warningLabel.grid(row=9, columnspan=2)
        else:
            #If the text does not match, show an alert
            self.warningLabel["text"]="Hidden phrase challenge failed"
            self.warningLabel.grid(row=9, columnspan=2)

    #Check if the user is in the file and return the data in a list
    def findUserData(self, username):
        try:
            #open the local file in reading mode
            users = open("users.txt", "r")
            #read all the lines of the text and put them in a list
            lines = users.readlines()
            #Check each line
            for line in lines:
                #The user data is separated by ; so split the text and check if the username matches the first field in the line
                data = line.split(";")
                if data[0]==username:
                    #If found, return the data
                    return data
            return None
        except FileNotFoundError:
            #if the file does not exists, no user is registered yet
            return None

    #generates 3 random positions from 0 to 9 to ask the user for the hidden phrase challenge
    def getPhraseChallenge(self):
        #create an empty list
        indexes = []
        #3 times loop
        for i in range(1,4):
            #generate random number
            num = random.randint(0,10)
            #if the number is already in the list, search for a new one that isn't
            while num in indexes:
                num = random.randint(0,10)
            #add the number to the list
            indexes.append(num)
        #return the list
        return indexes

    def register(self):
        #clear any previous warnings if any
        self.clearWarnings()
        #get the username, password and hidden phrase input fields
        username = self.usernameEntry.get()
        password = self.passwordEntry.get()
        hiddenPhrase = self.hiddenPhraseEntry.get()
        #Check if the hidden phrase is 10 characters long and alphanumeric
        if hiddenPhrase.isalnum() and len(hiddenPhrase) == 10:
            #Check that the username isn't already been registered
            if not self.findUserData(username):
                #Open the local file in append mode (to write new data at the end of the file)
                users = open("users.txt", "a+")
                #creates the structure of the saved data (username;password;hiddenphrase)
                data = username + ";" + password + ";" + hiddenPhrase + "\n"
                #write the data to the file and close it
                users.write(data)
                users.close()
                #Clean the form and show a confirmation message
                self.cleanWidgets()
                self.warningLabel["text"]="Account setup successful"
                self.warningLabel.grid(row=7, columnspan=2)
            else:
                #Show an alert for a duplicate username entry
                self.warningLabel["text"]="Username already exists"
                self.warningLabel.grid(row=7, columnspan=2)
        else:
            #Show an alert stating the hidden phrase constraints
            self.warningLabel["text"]="The hidden phrase needs to be alphanumeric\n with no spaces and 10 characters long"
            self.warningLabel.grid(row=7, columnspan=2)

    def registerForm(self):
        self.cleanWidgets()
        #Display the username, password and hidden phrase input fields and labels for the register form
        self.usernameLabel.grid(row=3, column=0, padx=10)
        self.usernameEntry.grid(row=3, column=1, padx=10)
        self.passwordLabel.grid(row=4, column=0, padx=10)
        self.passwordEntry.grid(row=4, column=1, padx=10)
        self.hiddenPhraseLabel.grid(row=5, column=0, padx=10)
        self.hiddenPhraseEntry.grid(row=5, column=1, padx=10)
        #display the register button
        self.doRegisterBtn.grid(row=6, columnspan=2, pady=10)

    def loginForm(self):
        self.cleanWidgets()
        #Display the username and password inut fields for the login form
        self.usernameLabel.grid(row=3, column=0, padx=10)
        self.usernameEntry.grid(row=3, column=1, padx=10)
        self.passwordLabel.grid(row=4, column=0, padx=10)
        self.passwordEntry.grid(row=4, column=1, padx=10)
        #Display the login button
        self.doLoginBtn.grid(row=6, columnspan=2, pady=10)

    def cleanWidgets(self):
        #Hide all the login/register related items (if present)
        self.usernameLabel.grid_forget()
        self.usernameEntry.grid_forget()
        self.passwordLabel.grid_forget()
        self.passwordEntry.grid_forget()
        self.hiddenPhraseLabel.grid_forget()
        self.hiddenPhraseEntry.grid_forget()
        self.doRegisterBtn.grid_forget()
        self.doLoginBtn.grid_forget()
        self.warningLabel.grid_forget()
        self.confirmPhraseLabel.grid_forget()
        self.confirmPhraseBtn.grid_forget()

    def clearWarnings(self):
        #hide all the warning/messages in the UI (if any)
        self.warningLabel.grid_forget()
        self.confirmPhraseLabel.grid_forget()
        self.confirmPhraseBtn.grid_forget()

#Creates a root Frame from Tkinter
root = tk.Tk()
#Set the frame title
root.title("WELCOME")
#Creates a new window with the root frame
app = MainWindow(master=root)
#start/display the window
app.mainloop()