Return a non iterator from __iter__

Question

class test(object):
    def __init__(self):
        pass
    def __iter__(self):
        return \"my string\"

o = test()
print iter(o)

Why does th

Answer 1

To answer your specific question. Python2 appears to check for the presence of a .next class attribute:

>>> class test(object):
...     next = None
...     def __iter__(self):
...         return self
... 
>>> print iter(test())
<__main__.test object at 0x7fcef75c2f50>

An instance attribute won't do:

>>> class test(object):
...    def __init__(self):
...        self.next = None
...    def __iter__(self):
...        return self
... 
>>> print iter(test())
Traceback (most recent call last):
  File "", line 1, in 
TypeError: iter() returned non-iterator of type 'test'