"Too many values to unpack" Exception

Question

That exception means that you are trying to unpack a tuple, but the tuple has too many values with respect to the number of target variables. For example: this work, and prints 1, then 2, then 3

def returnATupleWithThreeValues():
    return (1,2,3)
a,b,c = returnATupleWithThreeValues()
print a
print b
print c

But this raises your error

def returnATupleWithThreeValues():
    return (1,2,3)
a,b = returnATupleWithThreeValues()
print a
print b

raises

Traceback (most recent call last):
  File "c.py", line 3, in ?
    a,b = returnATupleWithThreeValues()
ValueError: too many values to unpack

Now, the reason why this happens in your case, I don't know, but maybe this answer will point you in the right direction.

try unpacking in one variable,

python will handle it as a list,

then unpack from the list

def returnATupleWithThreeValues():
    return (1,2,3)
a = returnATupleWithThreeValues() # a is a list (1,2,3)
print a[0] # list[0] = 1
print a[1] # list[1] = 2
print a[2] # list[2] = 3

This problem looked familiar so I thought I'd see if I could replicate from the limited amount of information.

A quick search turned up an entry in James Bennett's blog here which mentions that when working with the UserProfile to extend the User model a common mistake in settings.py can cause Django to throw this error.

To quote the blog entry:

The value of the setting is not "appname.models.modelname", it's just "appname.modelname". The reason is that Django is not using this to do a direct import; instead, it's using an internal model-loading function which only wants the name of the app and the name of the model. Trying to do things like "appname.models.modelname" or "projectname.appname.models.modelname" in the AUTH_PROFILE_MODULE setting will cause Django to blow up with the dreaded "too many values to unpack" error, so make sure you've put "appname.modelname", and nothing else, in the value of AUTH_PROFILE_MODULE.

If the OP had copied more of the traceback I would expect to see something like the one below which I was able to duplicate by adding "models" to my AUTH_PROFILE_MODULE setting.

TemplateSyntaxError at /

Caught an exception while rendering: too many values to unpack

Original Traceback (most recent call last):
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/debug.py", line 71, in render_node
    result = node.render(context)
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/debug.py", line 87, in render
    output = force_unicode(self.filter_expression.resolve(context))
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/__init__.py", line 535, in resolve
    obj = self.var.resolve(context)
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/__init__.py", line 676, in resolve
    value = self._resolve_lookup(context)
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/template/__init__.py", line 711, in _resolve_lookup
    current = current()
  File "/home/brandon/Development/DJANGO_VERSIONS/Django-1.0/django/contrib/auth/models.py", line 291, in get_profile
    app_label, model_name = settings.AUTH_PROFILE_MODULE.split('.')
ValueError: too many values to unpack

This I think is one of the few cases where Django still has a bit of import magic that tends to cause confusion when a small error doesn't throw the expected exception.

You can see at the end of the traceback that I posted how using anything other than the form "appname.modelname" for the AUTH_PROFILE_MODULE would cause the line "app_label, model_name = settings.AUTH_PROFILE_MODULE.split('.')" to throw the "too many values to unpack" error.

I'm 99% sure that this was the original problem encountered here.