Nth prime: sync expected test results and input data with problem-spe…

…cifications (#1812)

exercises/nth-prime/example.py

@@ -2,33 +2,33 @@
 from math import sqrt
 
 
-def nth_prime(n):
-    if n < 1:
-        raise ValueError('The parameter `n` has to be a positive number.')
+def prime(number):
+    if number < 1:
+        raise ValueError('The parameter `number` has to be a positive number.')
 
     known = []
     candidates = prime_candidates()
 
-    def is_prime(m):
-        sqrt_m = sqrt(m)
-        for k in known:
-            if k > sqrt_m:
+    def is_prime(candidate):
+        sqrt_candidate = sqrt(candidate)
+        for item in known:
+            if item > sqrt_candidate:
                 return True
-            elif m % k == 0:
+            elif candidate % item == 0:
                 return False
         return True
 
-    while len(known) < n:
-        x = next(candidates)
-        if is_prime(x):
-            known.append(x)
+    while len(known) < number:
+        next_one = next(candidates)
+        if is_prime(next_one):
+            known.append(next_one)
 
-    return known[n - 1]
+    return known[number - 1]
 
 
 def prime_candidates():
     yield 2
     yield 3
-    for n in count(6, 6):
-        yield n - 1
-        yield n + 1
+    for number in count(6, 6):
+        yield number - 1
+        yield number + 1

exercises/nth-prime/nth_prime.py

@@ -1,2 +1,2 @@
-def nth_prime(positive_number):
+def nth_prime(number):
     pass

exercises/nth-prime/nth_prime_test.py

@@ -1,32 +1,32 @@
 import unittest
 
-from nth_prime import nth_prime
+from nth_prime import prime
 
 
 # Tests adapted from `problem-specifications//canonical-data.json` @ v2.1.0
 
 class NthPrimeTest(unittest.TestCase):
     def test_first_prime(self):
-        self.assertEqual(nth_prime(1), 2)
+        self.assertEqual(prime(1), 2)
 
     def test_second_prime(self):
-        self.assertEqual(nth_prime(2), 3)
+        self.assertEqual(prime(2), 3)
 
     def test_sixth_prime(self):
-        self.assertEqual(nth_prime(6), 13)
+        self.assertEqual(prime(6), 13)
 
     def test_big_prime(self):
-        self.assertEqual(nth_prime(10001), 104743)
+        self.assertEqual(prime(10001), 104743)
 
     def test_there_is_no_zeroth_prime(self):
         with self.assertRaisesWithMessage(ValueError):
-            nth_prime(0)
+            prime(0)
 
     # additional track specific test
     def test_first_twenty_primes(self):
         self.assertEqual([2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31,
                           37, 41, 43, 47, 53, 59, 61, 67, 71],
-                         [nth_prime(n) for n in range(1, 21)])
+                         [prime(n) for n in range(1, 21)])
 
     # Utility functions
     def setUp(self):