|
| 1 | +""" |
| 2 | +A palindromic prime is a prime number that is also palindromic, meaning it remains |
| 3 | +the same when its digits are reversed. |
| 4 | +
|
| 5 | +For more information about palindromic primes, refer to: |
| 6 | +https://en.wikipedia.org/wiki/Palindromic_prime |
| 7 | +""" |
| 8 | + |
| 9 | + |
| 10 | +def is_prime(number: int) -> bool: |
| 11 | + """ |
| 12 | + Check if a number is prime. |
| 13 | +
|
| 14 | + Args: |
| 15 | + number: A positive integer. |
| 16 | +
|
| 17 | + Returns: |
| 18 | + True if the number is prime, False otherwise. |
| 19 | +
|
| 20 | + Raises: |
| 21 | + ValueError: If number is not a positive integer. |
| 22 | +
|
| 23 | + Examples: |
| 24 | + >>> is_prime(2) |
| 25 | + True |
| 26 | + >>> is_prime(3) |
| 27 | + True |
| 28 | + >>> is_prime(88) |
| 29 | + False |
| 30 | + >>> is_prime(1) |
| 31 | + False |
| 32 | + >>> is_prime(9679) |
| 33 | + True |
| 34 | + >>> is_prime(0) |
| 35 | + Traceback (most recent call last): |
| 36 | + ... |
| 37 | + ValueError: Input must be a positive integer. |
| 38 | + >>> is_prime(-17) |
| 39 | + Traceback (most recent call last): |
| 40 | + ... |
| 41 | + ValueError: Input must be a positive integer. |
| 42 | + >>> is_prime(9.51) |
| 43 | + Traceback (most recent call last): |
| 44 | + ... |
| 45 | + ValueError: Input must be a positive integer. |
| 46 | + >>> is_prime("261") |
| 47 | + Traceback (most recent call last): |
| 48 | + ... |
| 49 | + ValueError: Input must be a positive integer. |
| 50 | + """ |
| 51 | + if not isinstance(number, int) or number <= 0: |
| 52 | + raise ValueError("Input must be a positive integer.") |
| 53 | + |
| 54 | + if 1 < number < 4: |
| 55 | + return True |
| 56 | + elif number < 2 or (number % 2 == 0): |
| 57 | + return False |
| 58 | + |
| 59 | + # Return True if number is not divisible by any odd number up to its square root |
| 60 | + return all(number % i != 0 for i in range(3, int(number**0.5) + 1, 2)) |
| 61 | + |
| 62 | + |
| 63 | +def palindromic_prime_check(number: int) -> bool: |
| 64 | + """ |
| 65 | + Check if a number is a palindromic prime number. |
| 66 | +
|
| 67 | + Args: |
| 68 | + number: A positive integer. |
| 69 | +
|
| 70 | + Returns: |
| 71 | + True if the number is a palindromic prime number, False otherwise. |
| 72 | +
|
| 73 | + Raises: |
| 74 | + ValueError: If number is not a positive integer. |
| 75 | +
|
| 76 | + Examples: |
| 77 | + >>> palindromic_prime_check(13) |
| 78 | + False |
| 79 | + >>> palindromic_prime_check(131) |
| 80 | + True |
| 81 | + >>> palindromic_prime_check(121) |
| 82 | + False |
| 83 | + >>> palindromic_prime_check(929) |
| 84 | + True |
| 85 | + >>> palindromic_prime_check(2) |
| 86 | + True |
| 87 | + >>> palindromic_prime_check(7) |
| 88 | + True |
| 89 | + >>> palindromic_prime_check(0) |
| 90 | + Traceback (most recent call last): |
| 91 | + ... |
| 92 | + ValueError: Input must be a positive integer. |
| 93 | + >>> palindromic_prime_check(-131) |
| 94 | + Traceback (most recent call last): |
| 95 | + ... |
| 96 | + ValueError: Input must be a positive integer. |
| 97 | + >>> palindromic_prime_check(1.9) |
| 98 | + Traceback (most recent call last): |
| 99 | + ... |
| 100 | + ValueError: Input must be a positive integer. |
| 101 | + >>> palindromic_prime_check("hello") |
| 102 | + Traceback (most recent call last): |
| 103 | + ... |
| 104 | + ValueError: Input must be a positive integer. |
| 105 | + """ |
| 106 | + if not isinstance(number, int) or number <= 0: |
| 107 | + raise ValueError("Input must be a positive integer.") |
| 108 | + |
| 109 | + if is_prime(number): |
| 110 | + number_str = str(number) |
| 111 | + if number_str == number_str[::-1]: |
| 112 | + return True |
| 113 | + return False |
| 114 | + |
| 115 | + |
| 116 | +if __name__ == "__main__": |
| 117 | + import doctest |
| 118 | + |
| 119 | + doctest.testmod() |
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