for — Advanced Playground

Starts a loop that iterates over a sequence or iterable

Python Playground

class FibSequence:
    """Yields Fibonacci numbers up to a maximum."""
    def __init__(self, max_val):
        self.max_val = max_val

    def __iter__(self):
        a, b = 0, 1
        while a <= self.max_val:
            yield a
            a, b = b, a + b

fibs = FibSequence(100)
print(list(fibs))

# Can iterate multiple times (creates new generator each time)
for n in FibSequence(20):
    print(n, end=" ")
print()

Output

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Implementing __iter__ as a generator makes your class iterable. Using yield means each FibSequence can be iterated independently.

Challenge

Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?

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