Iterator instances not independent

Hello all.

I created a SequenceInt class for iteration but different instances do not seem independent.  The code looks like:

class SequenceInt:
    def __init__(self, last=10):
        self.val = 0
        self.LAST = last

    def __iter__(self):
        self.val = 0
        return self

    def __next__(self):
        if (self.hasNext()):
            self.val += 1
        else:
            raise StopIteration
        return self.val

    def __len__(self):
        return self.LAST - self.val

    def hasNext(self):
        return bool(len(self))

The main body of the test application looks like:

seqA = SequenceInt()
seqB = SequenceInt(5)
itB = iter(seqB)
itA = iter(seqA)

for x in seqA:
    if (seqB.hasNext()):
        bStr = str(next(itB))
    else:
        bStr = "done"
    print("A =", next(itA), "B =", bStr)

The output looks like:

A = 2 B = 1
A = 4 B = 2
A = 6 B = 3
A = 8 B = 4
A = 10 B = 5

The question is why does A increment by 2?
Aren't the two iterators independent of each other?
This doesn't seem too complex to me.

Python version is: 3.9.6 (default, Oct 17 2025, 17:15:53) [Clang 17.0.0 (clang-1700.4.4.1)]  on Mac OS 26.1

Looking forward to any help understanding why this is happening.
Fran

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