What is the difference between dict.items() and dict.iteritems() in Python2?

Question

Are there any applicable differences between dict.items() and dict.iteritems()?

From the Python docs:

dict.items(): Return a

Answer 1

You asked: 'Are there any applicable differences between dict.items() and dict.iteritems()'

This may help (for Python 2.x):

>>> d={1:'one',2:'two',3:'three'}
>>> type(d.items())

>>> type(d.iteritems())

You can see that d.items() returns a list of tuples of the key, value pairs and d.iteritems() returns a dictionary-itemiterator.

As a list, d.items() is slice-able:

>>> l1=d.items()[0]
>>> l1
(1, 'one')   # an unordered value!

But would not have an __iter__ method:

>>> next(d.items())
Traceback (most recent call last):
  File "", line 1, in 
TypeError: list object is not an iterator

As an iterator, d.iteritems() is not slice-able:

>>> i1=d.iteritems()[0]
Traceback (most recent call last):
  File "", line 1, in 
TypeError: 'dictionary-itemiterator' object is not subscriptable

But does have __iter__:

>>> next(d.iteritems())
(1, 'one')               # an unordered value!

So the items themselves are same -- the container delivering the items are different. One is a list, the other an iterator (depending on the Python version...)

So the applicable differences between dict.items() and dict.iteritems() are the same as the applicable differences between a list and an iterator.