Reference library

Comprehensions & generators

List/dict/set comprehensions, generator expressions, and lazy iteration.

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Comprehensions & generators easy

How to Generate a Collatz Sequence in Python

Generate the Collatz sequence for a given positive integer by repeatedly applying the 3n+1 rule until reaching 1.

collatz sequence loops
Python 
def collatz_sequence(n):
    if n <= 0:
        raise ValueError("n must be a positive integer")
    sequence = [n]
    while n != 1:
        if n % 2 == 0:
            n = n // 2
        else:
            n = 3 * n + 1
        sequence.append(n)
    return sequence

if __name__ == "__main__":
    start = 7
    result…
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Comprehensions & generators — Python code examples

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