Django: Why 'Class' object is not iterable

Question

I built a dictionary list like this

lst = [{'name': nameobj, Classobj1: "string", Classobj2: "string"}, \
{'name': nameobj, Classobj1: "string", Classobj2: "string"}]

and I'm using

for dic in lst:
   for k,v in dic:   # here is the line has probloem! What it happens?
       #process

The error message is like "Classname" object is not iterable.

lacker · Accepted Answer · 2011-01-19 00:16:21Z

5

Iterating over a dictionary just iterates over the keys, not key-value pairs. So on the line

for k,v in dic:

Python is taking just a key, such as Classobj1, and trying to unpack it to match it to the tuple k,v. Since Classobj1 can't be iterated over, it can't be unpacked to match two items, which is why you get this error.

To iterate over key-value pairs, use items() or iteritems():

for k,v in dic.items():

answered Jan 19, 2011 at 0:16

lacker

5,5806 gold badges38 silver badges39 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Femaref · Accepted Answer · 2011-01-19 00:03:47Z

1

You need to use dic.iteritems().

answered Jan 19, 2011 at 0:03

Femaref

61.5k8 gold badges145 silver badges176 bronze badges

4 Comments

user469652 Over a year ago

Thanks, but what happened to me~

Maxence SCHMITT Over a year ago

That is right too. Do you know if there is any differences between our solutions, I mean about speed?Thanks

Femaref Over a year ago

I only know rudimentary python. I don't think there is and if there is, it is minimal.

keegan3d Over a year ago

The difference between keys and iteritems is what's returned. Keys will return an array of keys where iteritems will return an iterator that yields a tuple(key, value). In most cases it's better to use iterators in loops because they do not make a copy of the data.

Maxence SCHMITT · Accepted Answer · 2011-01-19 00:05:08Z

0

Try to use

for dic in lst:
    for key in dic.keys():
     /* process dic[key] */

answered Jan 19, 2011 at 0:05

Maxence SCHMITT

6294 silver badges12 bronze badges

1 Comment

keegan3d Over a year ago

It appears from the code posted that he wants the key and the value, .keys() will only return the keys.

primroot · Accepted Answer · 2011-01-19 00:20:17Z

0


for dic in lst:
   for k,v in dic.iteritems():   # just added a call to iteritems
       #process

You get the '<class obj> is not iterable' error because a dict yields its keys when iterating over it, so when you reach say Classobj1 the program expects Classobj1 to be an iterable object that will yield values for k,v.

edited Jan 19, 2011 at 0:20

answered Jan 19, 2011 at 0:14

primroot

1,7061 gold badge15 silver badges17 bronze badges

Collectives™ on Stack Overflow

Django: Why 'Class' object is not iterable

4 Answers 4

Comments

4 Comments

1 Comment

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

4 Answers 4

Comments

4 Comments

1 Comment

Comments

Your Answer

Sign up or log in

Post as a guest

Related