"object is not iterable" error on my python implementation of iterable

Question

I am trying to create a iterable class but have been banging my head on a wall so to speak, getting "object is not iterable". This is my code:

class myiterable:
    def __init__(self, somelist):
        self.i = 0
        self.l = somelist

    def __iter__(self):
        return self

    def __next__(self):
        if self.i < len(self.l):
            self.i = self.i + 1
            return self.l[self.i-1]
        else:
            raise StopIteration



for i in myiterable([1, 2, 3, 4, 5]):
    print(i)

What's wrong? I have also tried next(self) in lieu of __next__(self) to no avail!

Look at your indentation. See anything wrong here? Please do correct it if this is not what you meant. If you don't see anything wrong, look harder and that's your problem. — Martijn Pieters, Aug 29 '13 at 08:46
`++self.i` is **not** python syntax, btw. Use `self.i += 1`. Your version will just lead to an infinite loop instead. — Martijn Pieters, Aug 29 '13 at 08:47
If this is the fixed version then you just found your problem. `__iter__` and `__next__` are not methods on `myiterable`; they are nested functions inside `__init__`. — Martijn Pieters, Aug 29 '13 at 08:51

score 5 · Answer 1 · answered Aug 29 '13 at 08:50

There are several problems with your code:

indentation
if you are on python 2, you should have defined next() method instead of __next__() (leave it as is if on python 3)
++self.i should be replaced with self.i += 1
self.l[i-1] should be replaced with self.l[self.i-1]

class myiterable:
    def __init__(self, somelist):
        self.i = 0
        self.l = somelist

    def __iter__(self):
        return self

    def next(self):
        if self.i < len(self.l):
            self.i += 1
            return self.l[self.i-1]
        else:
            raise StopIteration


for i in myiterable([1, 2, 3, 4, 5]):
    print(i)

prints:

Python 3 uses `.__next__()`, **not** `.next()`. – Martijn Pieters Aug 29 '13 at 08:50 — Martijn Pieters, Aug 29 '13 at 08:50
The OP uses `print(i)`, you can assume Python 3 here. – Martijn Pieters Aug 29 '13 at 08:52 — Martijn Pieters, Aug 29 '13 at 08:52

score 3 · Accepted Answer · answered Aug 29 '13 at 08:48

3

If you just copied your code, then it should be because of bad indent. Pull __iter__ and __next__ to same indent as __init__.

answered Aug 29 '13 at 08:48

TieDad

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My God! I cannot believe I fell for such a stupid mistake! Thanks man! – Tarik Aug 29 '13 at 08:52

"object is not iterable" error on my python implementation of iterable

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