Storing Username And Password Into A Dictionary?

Currently at the moment im working a small login screen in python, What i want it to do is ask a user to register if theyre isnt a account already created, But one small problem im

Solution 1:

you dont ... you save a hash into a dictionary (a hash is simpley a non reversable encoding)

eg: md5("password") == '5f4dcc3b5aa765d61d8327deb882cf99'

however there is no real way to go from that back to the password

nothing_does_this('5f4dcc3b5aa765d61d8327deb882cf99') == "password"

(not entirely true... but close enough fo the concept)

import hashlib
defcreate_users()
   users = {}
   whileTrue:
      username = raw_input("Enter Username:")
      password = raw_input("Enter Password:")
      users[username] = hashlib.md5(password).hexdigest()
      if raw_input("continue?")[0].lower() != "y":
          return users

deflogin(userdict):
    username = raw_input("Username:")
    password = raw_input("Password:")
    return userdict.get(username,None) == hashlib.md5(password).hexdigest()

users = create_users()
if login(users):
   print"Double Winning!!!"else:
   print"You Lose Sucka!!!"

as pointed out md5 is not a very secure hash, there are much better ones to use sha256 is pretty good still I think, bcrypt is even better (for some definition of better) ... however md5 is a simple hash to help with understanding what they are..

Solution 2:

If you already have constructed this dictionary, you can save it to a file with pickle.

pickle.dump( user_dict, open( "save.p", "wb" ) )

However, you should be aware of best practices when storing passwords and make sure you are storing a securely hashed version of the password rather than its value in plaintext.