How to use the iterator class?

Question

Im trying to create a iterator class that will give me a path throw a tree graph, which every iteration it will return the next step according to certain conditions.

So i looked up how to do this here : Build a Basic Python Iterator

and this is what i wrote so far :

def travel_path_iterator(self, article_name):
    return Path_Iter(article_name)


class Path_Iter:

    def __init__(self,article):
        self.article=article

    def __iter__(self):
        return next(self)

    def __next__(self):
        answer= self.article.get_max_out_nb()
        if answer != self.article.get_name():
            return answer
        else:
            raise StopIteration

But I have a problem to call this class. my output is always :

<__main__.Path_Iter object at 0x7fe94049fc50>

any guesses what im doing wrong ?

your __next__-method looks weird. Does get_max_out_nb results in the next answer each time called? — Daniel
– Daniel, Commented Dec 27, 2015 at 22:50
It would be simpler to write a generator function yielding values. — Open AI - Opting Out
– Open AI - Opting Out, Commented Dec 28, 2015 at 0:42

Daniel · Accepted Answer · 2015-12-27 22:36:55Z

2

While Path_Iter is already an iterator, the __iter__-method should return self:

def __iter__(self):
    return self

Next, to iterate an iterator, you need some kind of loop. E.g. to print the contents, you could convert the iterator to a list:

print list(xyz.travel_path_iterator(article_name))

answered Dec 27, 2015 at 22:36

Daniel

42.9k4 gold badges57 silver badges82 bronze badges

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

3 Comments

limitless Over a year ago

i write this in the iterator class or in the function ? there is no need to recursion right ?

limitless Over a year ago

where i need to print list(xyz.travel_path_iterator(article_name))? in the PathIter class ?

Daniel Over a year ago

outside the class, it's an example, how you can use iterators.

Open AI - Opting Out · Accepted Answer · 2015-12-28 00:48:11Z

0

Using a generator function:

def travel_path_generator(article):
    while True:
        answer = article.get_max_out_nb()
        if answer == article.get_name()
            break
        else:
            yield answer

answered Dec 28, 2015 at 0:48

Open AI - Opting Out

24.3k7 gold badges65 silver badges102 bronze badges

Collectives™ on Stack Overflow

How to use the iterator class?

2 Answers 2

3 Comments

Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

3 Comments

Comments

Linked

Related