Need help writing to an external dictionary

def register(users):
unr = raw_input('Desired Username: ')
if users.has_key(unr):
print 'Sorry, username is already taken'
else:
pr = raw_input('Enter Password: ')
users[unr] = pr

from usernames import users

register(users)

I want to write the new username and password to the dictionary permanently, not just in the memory. So that the file will contain that information the next time the user tries to log in.

I know that its insecure, but it is just for practice, how to write to the dictionary and external files. any help would be awesome!

You could probably use memory mapped files but the usual answer would be "investigate pickle and shelve modules."

http://docs.python.org/3/library

This probably isn't what you wanted but you could write to a file.

import ast

users = {} # initialise users dict which initialise will update

def writeToFile(): #call this whenever you change the dictionary
userFile = open('users.txt', 'w')
userFile.write(str(users))

def initialise(): #initialise dictionary from last time
usersFile = open('users.txt', 'r')
userDict = ast.literal_eval(usersFile.read())
for user in userDict: #you can edit globals within functions
users[user] = userDict[user]

probably also want to file.close() after each of those methods, and could put a try except around if you want too..