How do I call the function next() without type it again?

Question

The idea is to be able to call the next number every time it is called data, but as you know I cant type next() everytime in the code, is there a way to achieve that? thanks for your help.

class Sample():
    def __init__(self, begin, end):
        self.begin = begin
        self.end = end
        #self.counter = 0
    
    def number(self):
        for i in range(self.begin, self.end):
            #self.counter +=1
            yield i
            

instance = Sample(begin=525, end=535)
data = instance.number()

print(next(data))
print(next(data)) 
print(next(data))

I cant use loops this time becuse I want to get one number one by one everytime it called data, example call data: 526. calls data 527. calls data 527 like this. not 526,527,528,529...... thanks

You Sir, are looking for a callback, or the Observer Pattern I think :) ? — Morten Jensen, Nov 18 '22 at 18:35
I don't understand what is wrong with what you're doing. Sure you can type `next()` everytime. — quamrana, Nov 18 '22 at 18:37
Do the answers to this [question](https://stackoverflow.com/questions/4152376/how-to-get-the-n-next-values-of-a-generator-in-a-list-python) help at all? — quamrana, Nov 18 '22 at 18:39
Generally, you don't call `next` repeatedly like this. You use a `for` loop to call it for you. — chepner, Nov 18 '22 at 18:50
With regards to providing a [mcve], you could have simply written `data = iter(range(525, 536))`. — chepner, Nov 18 '22 at 18:52
hello, I cant use a loops this time becuse I want to get one number one by one everytime it called data, example call data: 526. calls data again 527 like this — wally, Nov 18 '22 at 18:55
@quamrana I dont want to hehe I want to call the number of the data eveytime its needed one by one. without having to type next() everytime. — wally, Nov 18 '22 at 19:16
Still don't understand; why not call next(data) every time it's needed then ? — Swifty, Nov 18 '22 at 19:17

score 1 · Accepted Answer · answered Nov 18 '22 at 19:35

You can hide the call to next() in a property getter.

class Sample():
    def __init__(self, begin, end):
        self.begin = begin
        self.end = end
        self._sequence = self.number()

    def number(self):
        for i in range(self.begin, self.end):
            yield i

    @property
    def counter(self):
        return next(self._sequence)

instance = Sample(begin=525, end=535)

print(instance.counter) # prints 525
print(instance.counter) # prints 526

However, if you use it this way, you'll need your own handler for the StopIteration exception that's raised when you reach the end of the iterator.

How do I call the function next() without type it again?

1 Answers1