Python while regular expressions help

[Aspect11]

So I am rewriting a bit of my code, but I have hit a roadblock. I am trying to have a while loop that will test for two regular expressions. My code is: (i added a bit of pseudocode btw)

def authentication():
    print("*------------------------------------------------------------*")
    file = open("users.txt")
    text = file.read()
    user1NameInput = input("What is your name, user 1?: ")
    user2NameInput = input("What is your name, user 2?: ")
    re_res1 = re.search(r'^{}, (.*)$'.format(user1NameInput), text, re.MULTILINE)
    re_res2 = re.search(r'^{}, (.*)$'.format(user2NameInput), text, re.MULTILINE)
    while re_res1 and re_res2:
    	ask for password and play game
    else:
    	add usernames to the file

 

[0x21]

I'd highly recommend creating a user class. This should get you started:

#!/usr/bin/env python3

import re

class User:
  def __init__(self, name):
	self.name = name
    
def auth(*users):
  with open("users.txt") as file:
    text = file.read()
    for user in users:
      res = re.search(r'^{}, (.*)$'.format(user.name), text, re.MULTILINE)
      while res:
        # Login
      else:
        # Register

if __name__ == '__main__':
  user1 = User('username1')
  user2 = User('username2')
  
  auth(user1, user2)

[Mira Yurizaki]

1 hour ago, DerpDiamonds1 said:

So I am rewriting a bit of my code, but I have hit a roadblock. I am trying to have a while loop that will test for two regular expressions. My code is: (i added a bit of pseudocode btw)

def authentication():
    print("*------------------------------------------------------------*")
    file = open("users.txt")
    text = file.read()
    user1NameInput = input("What is your name, user 1?: ")
    user2NameInput = input("What is your name, user 2?: ")
    re_res1 = re.search(r'^{}, (.*)$'.format(user1NameInput), text, re.MULTILINE)
    re_res2 = re.search(r'^{}, (.*)$'.format(user2NameInput), text, re.MULTILINE)
    while re_res1 and re_res2:
    	ask for password and play game
    else:
    	add usernames to the file

 

You can't have a while loop followed by an else statement. else is for the default case if an if-statement doesn't run.

 

You should be using an if-statement for checking to see if the regular expressions found something rather than using a while loop. If the point of the authentication function is to, well, authenticate, it doesn't make sense for it to handle the main loop to run the game.

 

EDIT: Never mind, I found Python allows for elses after whiles (which is weird, but okay)

Edited January 10, 2019 by Mira Yurizaki

[Aspect11]

So is there another way to authenticate usernames and passwords without using regular expressions. Mabey with an array?

[Meic]

It might be easier to authenticate/create one user at a time, something like:

 

def authenticate():
  username = input("What is your username?: ")
  with open('users.txt') as f:
    text = f.read()
  res = re.search(r'^{}, (.*)$'.format(username), text, re.MULTILINE)
  if res:
    password = input("What is the password for {}?: ".format(username))
  	# check password
  else:
    # create user
  return username
    
 
def run():
  print('User 1, Please log in.')
  user1 =  authenticate()
  print('User 2, Please log in.')
  user2 =  authenticate()
  # play game
        

 

[Mira Yurizaki]

22 hours ago, DerpDiamonds1 said:

So is there another way to authenticate usernames and passwords without using regular expressions. Mabey with an array?

Store the usernames and passwords in a structured format, like either as a JSON or a CSV. You can then break up the file into either objects (if you use JSON) or as a multi-dimensional list (CSV). Would recommend the JSON path because usernames are supposed to be unique, and so it'd be much easier to access the data blob you neeed.

 

Then you could just do stored_password == inputted_password

 

I'm guessing you're doing this for an exercise, but if you are thinking about doing serious deployment of this application, I strongly recommend you don't store plaintext passwords. At the very least, you should use a hashing algorithm like SHA1 or SHA2.

[Oliver123456]

23 hours ago, Meic said:

It might be easier to authenticate/create one user at a time, something like:

 

def authenticate():
  username = input("What is your username?: ")
  with open('users.txt') as f:
    text = f.read()
  res = re.search(r'^{}, (.*)$'.format(username), text, re.MULTILINE)
  if res:
    password = input("What is the password for {}?: ".format(username))
  	# check password
  else:
    # create user
  return username
    
 
def run():
  print('User 1, Please log in.')
  user1 =  authenticate()
  print('User 2, Please log in.')
  user2 =  authenticate()
  # play game
        

 

How can i then assign each username to user1 and user2?

[0x21]

1 hour ago, Oliver123456 said:

How can i then assign each username to user1 and user2?

Use a class.