Custom python iterator

python_iterator.py

class Fibonacci:
    def __init__(self, limit):
        self.limit = limit
        self.counter = 0
        self.fib_data = []
 
    def __iter__(self):
        return self
 
    def next(self):
        self.counter += 1
        if self.counter > self.limit:
            raise StopIteration
 
        if len(self.fib_data) < 2:
            self.fib_data.append(1)
        else:
            self.fib_data = [
                self.fib_data[-1], self.fib_data[-1] + self.fib_data[-2]
            ]
        return self.fib_data[-1]
# Case1
for i in Fibonacci(3):
    print(i)
# Output:
# 1
# 1
# 2

# Case2
iter_obj = Fibonacci(3)
print(next(iter_obj))
print(next(iter_obj))
print(next(iter_obj))
print(next(iter_obj))
# Output:
# 1
# 1
# 2
# Traceback (most recent call last):
#  File "fibonacci.py", line 30, in <module>
#    print next(iter_obj)
# StopIteration