mirror of
https://github.com/TheAlgorithms/Python.git
synced 2024-11-24 13:31:07 +00:00
04fae4db9b
* Made small improvements and shortened prime_check.py * improved descriptions on tests in prime_check.py * Ran black and isort
59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
"""Prime Check."""
|
|
|
|
import math
|
|
import unittest
|
|
|
|
|
|
def prime_check(number: int) -> bool:
|
|
"""Checks to see if a number is a prime.
|
|
|
|
A number is prime if it has exactly two factors: 1 and itself.
|
|
"""
|
|
|
|
if 1 < number < 4:
|
|
# 2 and 3 are primes
|
|
return True
|
|
elif number < 2 or not number % 2:
|
|
# Negatives, 0, 1 and all even numbers are not primes
|
|
return False
|
|
|
|
odd_numbers = range(3, int(math.sqrt(number) + 1), 2)
|
|
return not any(not number % i for i in odd_numbers)
|
|
|
|
|
|
class Test(unittest.TestCase):
|
|
def test_primes(self):
|
|
self.assertTrue(prime_check(2))
|
|
self.assertTrue(prime_check(3))
|
|
self.assertTrue(prime_check(5))
|
|
self.assertTrue(prime_check(7))
|
|
self.assertTrue(prime_check(11))
|
|
self.assertTrue(prime_check(13))
|
|
self.assertTrue(prime_check(17))
|
|
self.assertTrue(prime_check(19))
|
|
self.assertTrue(prime_check(23))
|
|
self.assertTrue(prime_check(29))
|
|
|
|
def test_not_primes(self):
|
|
self.assertFalse(
|
|
prime_check(-19),
|
|
"Negative numbers are excluded by definition of prime numbers.",
|
|
)
|
|
self.assertFalse(
|
|
prime_check(0),
|
|
"Zero doesn't have any positive factors, primes must have exactly two.",
|
|
)
|
|
self.assertFalse(
|
|
prime_check(1),
|
|
"One only has 1 positive factor, primes must have exactly two.",
|
|
)
|
|
self.assertFalse(prime_check(2 * 2))
|
|
self.assertFalse(prime_check(2 * 3))
|
|
self.assertFalse(prime_check(3 * 3))
|
|
self.assertFalse(prime_check(3 * 5))
|
|
self.assertFalse(prime_check(3 * 5 * 7))
|
|
|
|
|
|
if __name__ == "__main__":
|
|
unittest.main()
|