Function is_prime

maths/primelib.py:45–89

input: positive integer 'number' returns true if 'number' is prime otherwise false. >>> is_prime(3) True >>> is_prime(10) False >>> is_prime(97) True >>> is_prime(9991) False >>> is_prime(-1) Traceback (most recent call last): ... Asserti

(number: int)

def is_prime(number: int) -> bool:
    """
    input: positive integer 'number'
    returns true if 'number' is prime otherwise false.

    >>> is_prime(3)
    True
    >>> is_prime(10)
    False
    >>> is_prime(97)
    True
    >>> is_prime(9991)
    False
    >>> is_prime(-1)
    Traceback (most recent call last):
        ...
    AssertionError: 'number' must been an int and positive
    >>> is_prime("test")
    Traceback (most recent call last):
        ...
    AssertionError: 'number' must been an int and positive
    """

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

    status = True

    # 0 and 1 are none primes.
    if number <= 1:
        status = False

    for divisor in range(2, round(sqrt(number)) + 1):
        # if 'number' divisible by 'divisor' then sets 'status'
        # of false and break up the loop.
        if number % divisor == 0:
            status = False
            break

    # precondition
    assert isinstance(status, bool), "'status' must been from type bool"

    return status


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