[ACCEPTED]-django error 'too many values to unpack'-sqlite

Accepted answer
Score: 22

Edit: Updated in light of kibibu's correction.

I have encountered what I believe is this 13 same error, producing the message:

Caught ValueError while rendering: too many values to unpack

My form 12 class was as follows:

class CalcForm(forms.Form):
    item = forms.ChoiceField(choices=(('17815', '17816')))

Note that my choices type 11 here a tuple. Django official documentation 10 reads as follows for the choices arg:

An iterable 9 (e.g., a list or tuple) of 2-tuples to use 8 as choices for this field. This argument 7 accepts the same formats as the choices argument 6 to a model field.

src: https://docs.djangoproject.com/en/1.3/ref/forms/fields/#django.forms.ChoiceField.choices

This problem was solved 5 by my observing the documentation and using 4 a list of tuples:

class CalcForm(forms.Form):
    item = forms.ChoiceField(choices=[('17815', '17816')])

Do note that while the docs state any 3 iterable of the correct form can be used, a 2 tuple of 2-tuples did not work:

item = forms.ChoiceField(choices=(('17815', '17816'), ('123', '456')))

This produced 1 the same error as before.

Lesson: bugs happen.

Score: 2

You should use a ChoiceField instead of SmallIntegerField


Score: 1

If I had to guess, it's because whatever 4 is in the administrative template expects 3 a list of tuples, but you've instead supplied 2 a tuple of tuples (hence the "too many values"). Try 1 replacing with a list instead:

CATEGORY_CHOICES = [    # Note square brackets.
    (1, u'Appetizer'),
    (2, u'Bread'),
    (3, u'Dessert'),
    (4, u'Drinks'),
    (5, u'Main Course'),
    (6, u'Salad'),
    (7, u'Side Dish'),
    (8, u'Soup'),
    (9, u'Sauce/Marinade'),
    (10, u'Other'),        
Score: 1

Per http://code.djangoproject.com/ticket/972 , you need to move the assignment CATEGORY_CHOICES = ... outside the 1 class statement.

Score: 0

I got it working. Most of the 'too many 9 values to unpack' errors that i came across 8 while googling were Value Error types. My 7 error was a Template Syntax type. To load 6 my recipe table i had imported a csv file. I 5 was thinking maybe there was a problem somewhere 4 in the data that sqlite allowed on import. So 3 i deleted all data and then added 2 recipes 2 manually via django admin form. The list 1 of recipes loaded after that.


Score: 0

I just had the same problem... my cvs file 6 came from ms excel and the date fields gotten 5 the wrong format at saving time. I change 4 the format to something like '2010-05-04 3 13:05:46.790454' (excel gave me 5/5/2010 2 10:05:47) and voilaaaa no more 'too many 1 values to unpack’

Score: 0

kibibu's comment to Kreychek's answer is 20 correct. This isn't a Django issue but rather 19 an interesting aspect of Python. To summarize:

In 18 Python, round parentheses are used for both 17 order of operations and tuples. So:

foo = (2+2)

will 16 result in foo being 4, not a tuple who's 15 first and only element is 4: 4

foo = (2+2, 3+3)

will result 14 in foo being a two-dimensional tuple: (4,6)

To 13 tell Python that you want to create a one-dimensional 12 tuple instead of just denoting the order 11 of operations, use a trailing comma:

foo = (2+2,)

will 10 result in foo being a one-dimensional tuple 9 who's first and only element is 4: (4,)

So 8 for your scenario:

class CalcForm(forms.Form):
    item = forms.ChoiceField(choices=(('17815', '17816'),))

would give what you want. Using 7 a list is a great solution too (more Pythonic 6 in my opinion), but hopefully this answer 5 is informative since this can come up in 4 other cases.

For example:

print("foo: %s" % (foo))

may give an error 3 if foo is an iterable, but:

print("foo: %s" % (foo,))


print("foo: %s" % [foo])

will properly 2 convert foo to a string whether it's an 1 iterable or not.

Documentation: http://docs.python.org/2/tutorial/datastructures.html#tuples-and-sequences

Score: 0

This error IMO occurs when a function returns 2 three values, and you assign it to 2. e.g.:

def test():
a,b=test() <---three values returned, but only assigning to 2.

a,b,c=test() <---three 1 values returned, assigned to 3.OK

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