Writing invalid password to a text file

Question

First time programming!!
I've created a password checker that first checks to see if the password is between 6 and 14 characters long. If it isn't, it asks the user to re input a password. Once accepted it, then checks the password strength and outputs whether the password is strong or weak. I am trying to figure out how to record every invalid password attempt to a text file . that records whether it was less than min_length or greater than max_length with date and time and I'm absolutely lost.

I have looked up many sites and tutorials for possible solutions but don't see a possible solution

MIN_PASSWORD_LENGTH = 6
MAX_PASSWORD_LENGTH = 14
password = input("Enter Your Password: ")
password_length = len(password)

while True:
    if password_length < MIN_PASSWORD_LENGTH:
        print("Password Rejected - Password must be between 6 and 14 characters long")
        password = input("Enter your password: ")
   elif password_length > MAX_PASSWORD_LENGTH:
        print("Password Rejected - Password must be between 6 and 14 characters long")
        password = input("Enter your password: ")
    else:
        print("Password Accepted")
        break

special = ['!','@','#','$','%','^','&','*','(',')']
letters_found = 0
digits_found = 0
specials_found = 0
for ch in password:
    if ch.isalpha():
        letters_found = 1
    if ch.isdigit():
        digits_found = 1
    if ch in special:
        specials_found = 1
    if digits_found and letters_found and specials_found:
        break

password_strength = letters_found + digits_found + specials_found
if password_strength >=2:
    message = "Password is Strong!"
else:
    message = ",Password is Weak!"
print("Your Password is",(password_length),"characters long.",(message))

Would like to be able record everytime a user enters an invalid password and record the date time, and the reason why it was invalid in this case less than 6 or greater than 14

Answer 1

I recommend the use of the logging module in Python:

import logging
logging.basicConfig(filename='example.log',level=logging.DEBUG)
logging.debug('This message should go to the log file')
logging.info('So should this')
logging.warning('And this, too')

Add this to your code where you want to log. You can use f-strings to modify these messages and log the password as well.

Answer 2

For a first time programming, this is actually really good code! In python, it is very easy to write text to a file and can be done with a 'with' statement. Because you are also looking to record the date, you can use pythons inbuilt datetime module for this. I don't know exactly the way you want to structure it, since it seems the data is related you could use a relational database like SQLite, but I will keep this simple with a text document. Change your code at the while True to the following:

with open("password_log.txt", 'a') as doc:
    date = datetime.now()
    dateString = datetime.strftime(date, "%m/%d/%Y %H:%M:%S")
    while True:
        if password_length < MIN_PASSWORD_LENGTH:
            doc.write("too short," + dateString + "\n")
            print("Password Rejected - Password must be between 6 and 14 characters long")
            password = input("Enter your password: ")
        elif password_length > MAX_PASSWORD_LENGTH:
            doc.write("too long," + dateString + "\n")
            print("Password Rejected - Password must be between 6 and 14 characters long")
            password = input("Enter your password: ")
        else:
            print("Password Accepted")
            break

Up the very top of your code include from datetime import datetime. Feel free to ask for any clarifications on what this does. This will get it to work at the bare minimum, also storing any logs in a CSV-like format.

Answer 3

This is an improve on NightShade's answer but also a general improve overall. This is your first time coding so congratulations. I'm modifying a few things in your code for readibility, organization, efficiency and also expandability and reusability.

If there's anything you'd like me to explain please ask. Additionally, I modified the way you calculate the strength of the password but it can easily be put back to your original one. EDIT: As other users have suggested, you shouldn’t really store passwords. It’s okay for an exercise but you should build a habit of protecting passwords. If you intend on creating a login system later on, consider hashing the password, storing it in a secure location and then comparing hashes inputs with the stored hash. It adds some protection.

from datetime import datetime # importing the date module
MIN_PASSWORD_LENGTH = 6
MAX_PASSWORD_LENGTH = 14

# Auxilliary Functions
# Enclosing in functions so that they can be reused, separated and organized

def passCheck(input_password):
    date = datetime.now() 
    # sets the current date and time

    dateString = datetime.strftime(date, "%m/%d/%Y %H:%M:%S") 
    # formats the string to look like m/d/t h:m:s

    if len(input_password) < MIN_PASSWORD_LENGTH:
    # Using text formatting for cleanliness and readibility

        return(f"{dateString} ==> Password is too short: '{input_password}' (length = {len(input_password)})\n") 
    elif len(input_password) > MAX_PASSWORD_LENGTH:
        return(f"{dateString} ==> Password is too long: '{input_password}' (length = {len(input_password)})\n")
    else:
        return 0


def letter_analysis(input_password):
    special = ['!','@','#','$','%','^','&','*','(',')']
    letters_found = 0
    digits_found = 0
    specials_found = 0
    test = 0
    for ch in input_password:
    #Checking for isdigit(), isalpha() etc but adding everytime it finds it. You can change this.

        test = test + 1*ch.isdigit() 
        letters_found += 1 * ch.isalpha()
        digits_found += 1 * ch.isdigit()
        specials_found += 2 * (ch in special) 
        # I would suggest adding 2, for example, as special characters should be valued more

    return((letters_found and digits_found and specials_found, letters_found+digits_found+specials_found))
    #Returning a tuple where first index will be True if letters, digits and specials exist, and second index is the count.
    #Note: The count isn't a True count, since I'm counting special characters twice


## Main function

def main():
    input_password = input("Enter your password: ")
    try:
        with open("password_attempts.txt", "a") as passFile: 
        # Opening text file as append, so that it doesn't erase what's there

            passFile.write(passCheck(input_password)) 
            #Passing it the result of the check function.

        print(passCheck(input_password))
    except TypeError:
        print("Password Accepted") 
        #In case the return is 0, there will be TypeError. This is the case where it's accepted.

    strength = letter_analysis(input_password) 
    #strength now holds the tuple.

    evaluation = strength[0] + strength[1] 
    # Just an example. This is where strength is calculated and directly related to the letter analysis.

    if evaluation > 5:
    # Here you can use your judgement. I said 5 again as an example.
        print(f"Password is strong: '{input_password}' (length/evaluation = {len(input_password)}/{evaluation})")
    else:
        print(f"Password is weak: '{input_password}' (length/evaluation = {len(input_password)}/{evaluation})")
    main()

main()