Function isPrime

primelib/primelib.py:64–87

input: positive integer 'number' returns true if 'number' is prime otherwise false.

(number)

def isPrime(number):
    """
    input: positive integer 'number'
    returns true if 'number' is prime otherwise false.
    """

    # precondition
    assert isinstance(number, int) and (number >= 0), (
        "'number' must been an int and positive"
    )

    # 0 and 1 are none primes.
    if number <= 3:
        return number > 1
    elif number % 2 == 0 or number % 3 == 0:
        return False

    i = 5
    while i * i <= number:
        if number % i == 0 or number % (i + 2) == 0:
            return False
        i += 6

    return True


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