用户输入验证不会坚持

Question

I first want to thank anyone and everyone in advance for taking the time to help a scrub like me and appreciate your time in giving me a helping hand. So I am attempting to make a simple user creation script. Asking the user for their first and last name, concatenated the user's first letter of their first name with their last and concatenating it with a random number to create their user name. I then will prompt the user to create a password and have the password be a minimum of 6 characters long. After that, I ask the user to verify their password. I've been going crazy because when the program reaches the password verification step, it doesn't check for the 6 characters or verify that the passwords are the same and continues to the rest of the program.

This is a snippet of the password part:

# Ask the user for a password that's at least 6 characters long

 while True:
    password = input("Enter a password for this account: ")
# Verify that the user's input is 6 characters long

    if len(password) < 6:
        print("Your password must be at least 6 characters long! ")
# Has the user verify the password

    password = input("Please verify your password by typing it in again: ")
    if password == password:
        print("Thank you for confirming your password")
    else:
        print("Nope your password did not match")

And after all of that, I am having the "user" login with the new information that was generated. Using the username generated in the first part and using the password they input in the second and checking. The same thing, it skips the check and continues with the program. I am going insane because I've spent a couple of hours just learning some basics as I am a beginner with python.

Here is the full code:

def main():
print("You do the typin, I will take care of the rest!")

#User will be prompted to input their first and last name
firstname = input("Please give me your first name. ")
lastname = input("Thank you, now please give me your last name. ")

# The first and last name will be concatenated and the first letter of the
# users name will be attatched to their last name.

username = firstname[0] + lastname[:7]

# Now to generate the random number from 100-999 to attach to the new
# username

import random
from random import randint

print("Welcome", username + str(random.randint(100,999)))

import re

def sub():

# Ask the user for a password that's at least 6 charcaters long
 while True:
    password = input("Enter a password for this account: ")
# Verify that the users input is 6 charcters long
    if len(password) < 6:
        print("Your password must be at least 6 charcaters long! ")
# Has the user verify the password
    password = input("Please verify your password by typing it in again: ")
    if password == password:
        print("Thank you for confirming your password")
    else:
        print("Nope your password did not match")
# Now the user must login using the generated username from above
    username = input("Enter your generated username! ")
    if username == username:
        print("Correct!")
    else:
        print("I have never seen you before!")
    password = input("Now enter your accounts password: ")
    if password == password:
        print("You are now logged in!")
    else:
        print("FAIL")
    break
main()
sub()

Answer 1

So, there are many errors in your code. The first one is, there's nothing that stops the program from progressing if the password is less than 6 characters. Second, password == password will ALWAYS return true, because you're checking a var against itself. I re-wrote a bit of your code to try to help clarify your problem. I hope this helps! I also split the code into a few functions + added getpass ( https://docs.python.org/3/library/getpass.html )

from getpass import getpass # You can use this module to hide the password the user inputs
from random import randint

def generate_username():
    # Basic username generation, same thing you did
    print("You do the typin, I will take care of the rest!")
    firstname = input("Please give me your first name. ")
    lastname = input("Thank you, now please give me your last name. ")
    username = firstname[0] + lastname[:7] + str(randint(1, 99))
    # You can't concatenate strings and ints, so I convert the number to a string first
    print(f"Your username is: {username}") # f-strings (https://realpython.com/python-f-strings/)
    return username



def generate_password():
    while True:
        password = getpass("Enter a password for this account: ")
        confirm_password = getpass("Enter your password again: ") # Ask the user to enter the password a second time to confirm
        if password != confirm_password: # Check if the user entered the same password
            print("Passwords dont match!")
        elif len(password) < 6: # Check the length
            print("Your password must be at least 6 charcaters long! ")
        else: # If everythings all good
            print("Password is valid!")
            return password # Break the loop and return password value

def login(username, password):
    # Used to login a user
    while True:
        entered_username = input("Enter your username: ")
        entered_password = getpass("Enter your password: ")
        if username == entered_username and password == entered_password:
            # Confirm if username and password are correct, then exit the loop (or do something else)
            print("Login successful!")
            break
        else:
            print("Login failed, please confirm your username and password")

username = generate_username()
password = generate_password()
login(username, password)