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59 lines
1.7 KiB
Python
59 lines
1.7 KiB
Python
"""Prime Check."""
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import math
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import unittest
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def prime_check(number: int) -> bool:
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"""
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Check to See if a Number is Prime.
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A number is prime if it has exactly two dividers: 1 and itself.
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"""
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if number < 2:
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# Negatives, 0 and 1 are not primes
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return False
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if number < 4:
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# 2 and 3 are primes
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return True
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if number % 2 == 0:
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# Even values are not primes
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return False
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# Except 2, all primes are odd. If any odd value divide
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# the number, then that number is not prime.
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odd_numbers = range(3, int(math.sqrt(number)) + 1, 2)
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return not any(number % i == 0 for i in odd_numbers)
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class Test(unittest.TestCase):
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def test_primes(self):
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self.assertTrue(prime_check(2))
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self.assertTrue(prime_check(3))
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self.assertTrue(prime_check(5))
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self.assertTrue(prime_check(7))
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self.assertTrue(prime_check(11))
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self.assertTrue(prime_check(13))
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self.assertTrue(prime_check(17))
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self.assertTrue(prime_check(19))
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self.assertTrue(prime_check(23))
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self.assertTrue(prime_check(29))
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def test_not_primes(self):
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self.assertFalse(prime_check(-19), "Negative numbers are not prime.")
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self.assertFalse(
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prime_check(0), "Zero doesn't have any divider, primes must have two."
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)
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self.assertFalse(
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prime_check(1), "One just have 1 divider, primes must have two."
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)
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self.assertFalse(prime_check(2 * 2))
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self.assertFalse(prime_check(2 * 3))
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self.assertFalse(prime_check(3 * 3))
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self.assertFalse(prime_check(3 * 5))
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self.assertFalse(prime_check(3 * 5 * 7))
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if __name__ == "__main__":
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unittest.main()
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