Question

I am stuck in this small issue. I have a page where the user needs to log in. after login everything is fine. but once the user is logged in, if he hits the address bar with enter, this error – Key 'username' not found in <QueryDict: {}> is coming and showing error on the page.
this is my code for logging in:

if request.path == '/cms/':
    request.session['username'] = request.POST['username']
    request.session['password'] = request.POST['password']
    #check for login
    if User.objects.exists():
        u=User.objects.get(id=1)
        if u.username==request.session['username'] and u.password==request.session['password']:
            #do some stuff here, cos i am logged in

now, if i reload the page, it is fine, but with enter not. should i save the POST data into session? what is happenning here actually?

thanks a lot

Answer 1

What does request.POST contain? It does not contain the username. To find out what it contains you can print request.POST which should show up on your dev server, or you can log the value somewhere or you can enter debugger and inspect using import pdb; pdb.set_trace()

python dictionaries have get method for this case

request.POST.get('username')

If the key is not found it returns None by default instead of a KeyError

are you making a post request to your view?

<form method="post" action="/yoururlhere/">
  <input type="text" name="username" />
  <input type="text" name="password" />
  <input type="submit" value="submit" />
</form>

The above form would post the username and password fields. I think it is truley important to read https://docs.djangoproject.com/en/dev/topics/auth/ in its entirety, and learn how to use django built in user management. Django provides User objects (which it looks like you are using) and provides all the necessary functions to manage their authentication.

It is important because:

1. It is easier than doing it manually, once you learn it
2. Because it is easier it is most likely going to be faster than manageing authentication yourself
3. It is less prone to error than doing it manually. DJango source code has lots of eyes looking at it and lots of tests covering it. Please use the built in tools for the safety of your site.