Simple username and password application in Python

Question

I'm trying to build a simple login and password application using a dictionary. It works fine except the part where it checks if the login matches the password (in the bottom where it says "Login successful!"). If I were to create login 'a' and password 'b', and then create login 'b' and password 'a', it would log me in if I tried to log in with login 'a' and password 'a'. It just checks if those characters exist somewhere in the dictionary, but not if they are a pair. Any suggestions how to fix this? ``` users = {} status = "" while status != "q": status = raw_input("Are you a registered user? y/n? Press q to quit: ") if status == "n": #create new login createLogin = raw_input("Create login name: ") if createLogin in users: # check if login name exist in the dictionary print "Login name already exist!
" else: createPassw = raw_input("Create password: ") users[createLogin] = createPassw # add login and password print("
User created!
") elif status == "y": #login the user login = ra…

Accepted Answer

Right now you are checking if the given password, `passw`, matches any keys in `users` (not right). You need to see if the password entered matches that particular user's password. Since you have already checked if the username exists in the dictionary's keys you don't have to check again, so try something like:

```
if passw == users[login]:
    print "Login successful!
"
```

EDIT:

For your updated code, I'm going to assume by "infinite loop" you mean that you cannot use `q` to exit the program. It's because when you're inside `displayMenu`, you save user input in a local variable named `status`. This local variable does not refer to the same `status` where you are checking,

```
while status != "q": 
```

In other words, you are using the variable `status` in two different scopes (changing the inner scope does not change the outer).

There are many ways to fix this, one of which would be changing,

```
while status != "q":
    status = displayMenu()
```

And adding a return statement at the end of `displayMenu` like so,

```
return status
```

By doing this, you are saving the new value of `status` from local scope of `displayMenu` to global scope of your script so that the `while` loop can work properly.

Another way would be to add this line to the beginning of `displayMenu`,

```
global status
```

This tells Python that `status` within `displayMenu` refers to the global scoped `status` variable and not a new local scoped one.

Simple username and password application in Python

Solution

Problem