jgrant jgrant - 6 months ago 12
Python Question

Can a method within a class be generator?

Is it acceptable/Pythonic to use a method in a class as a generator? All the examples I have found show the yield statement in a function, not in a class.

Here is an example working code:

class SomeClass(object):
def first_ten(self):
for i in range(10):
yield i

def test(self):
for i in self.first_ten():
print i

SomeClass().test()

Answer

Yes, this is perfectly normal. For example, it is commonly used to implement an object.__iter__() method:

class SomeContainer(object):
    def __iter__(self):
        for elem in self._datastructure:
            if elem.visible:
                yield elem.value

However, don't feel limited by that common pattern; anything that requires iteration is a candidate for a generator method.