diff --git a/exercises/perfect-numbers/example.py b/exercises/perfect-numbers/example.py
index e80fefdcad..f2bc2d5a57 100644
--- a/exercises/perfect-numbers/example.py
+++ b/exercises/perfect-numbers/example.py
@@ -7,6 +7,17 @@ def divisor_generator(n):
                 yield n // i
 
 
-def is_perfect(n):
+def classify(n):
     ''' A perfect number equals the sum of its positive divisors. '''
-    return sum(divisor_generator(n)) + 1 == n
+    if n <= 0:
+        raise ValueError("Classification is only possible" +
+                         " for positive whole numbers.")
+
+    aliquot_sum = sum(divisor_generator(n)) + (1 if n > 1 else 0)
+
+    if aliquot_sum < n:
+        return "deficient"
+    elif aliquot_sum == n:
+        return "perfect"
+    else:
+        return "abundant"
diff --git a/exercises/perfect-numbers/perfect_numbers.py b/exercises/perfect-numbers/perfect_numbers.py
index df010e7b8c..0377abc50c 100644
--- a/exercises/perfect-numbers/perfect_numbers.py
+++ b/exercises/perfect-numbers/perfect_numbers.py
@@ -1,6 +1,2 @@
-def divisor_generator(number):
-    pass
-
-
-def is_perfect(number):
+def classify(number):
     pass
diff --git a/exercises/perfect-numbers/perfect_numbers_test.py b/exercises/perfect-numbers/perfect_numbers_test.py
index bb6de15d56..dd350818a6 100644
--- a/exercises/perfect-numbers/perfect_numbers_test.py
+++ b/exercises/perfect-numbers/perfect_numbers_test.py
@@ -1,42 +1,80 @@
 import unittest
 
-from perfect_numbers import is_perfect
+from perfect_numbers import classify
+
+# Tests adapted from `problem-specifications//canonical-data.json` @ v1.0.1
 
 
 class PerfectNumbersTest(unittest.TestCase):
+    def test_smallest_perfect_number(self):
+        self.assertIs(classify(6), "perfect")
 
-    def test_first_perfect_number(self):
-        self.assertIs(is_perfect(6), True)
+    def test_medium_perfect_number(self):
+        self.assertIs(classify(28), "perfect")
 
-    def test_no_perfect_number(self):
-        self.assertIs(is_perfect(8), False)
+    def test_large_perfect_number(self):
+        self.assertIs(classify(33550336), "perfect")
 
-    def test_second_perfect_number(self):
-        self.assertIs(is_perfect(28), True)
+    # Additional tests for this track
+    def test_third_perfect_number(self):
+        self.assertIs(classify(496), "perfect")
 
-    def test_abundant(self):
-        self.assertIs(is_perfect(20), False)
+    def test_fourth_perfect_number(self):
+        self.assertIs(classify(8128), "perfect")
 
-    def test_answer_to_the_ultimate_question_of_life(self):
-        self.assertIs(is_perfect(42), False)
+    def test_sixth_perfect_number(self):
+        self.assertIs(classify(8589869056), "perfect")
 
-    def test_third_perfect_number(self):
-        self.assertIs(is_perfect(496), True)
+    def test_seventh_perfect_number(self):
+        self.assertIs(classify(137438691328), "perfect")
+
+
+class AbundantNumbersTest(unittest.TestCase):
+    def test_smallest_abundant_number(self):
+        self.assertIs(classify(12), "abundant")
+
+    def test_medium_abundant_number(self):
+        self.assertIs(classify(30), "abundant")
+
+    def test_large_abundant_number(self):
+        self.assertIs(classify(33550335), "abundant")
+
+    # Additional tests for this track
+    def test_answer_to_the_ultimate_question_of_life(self):
+        self.assertIs(classify(42), "abundant")
 
     def test_odd_abundant(self):
-        self.assertIs(is_perfect(945), False)
+        self.assertIs(classify(945), "abundant")
 
-    def test_fourth_perfect_number(self):
-        self.assertIs(is_perfect(8128), True)
+    def test_even_abundant(self):
+        self.assertIs(classify(20), "abundant")
 
-    def test_fifth_perfect_number(self):
-        self.assertIs(is_perfect(33550336), True)
 
-    def test_sixth_perfect_number(self):
-        self.assertIs(is_perfect(8589869056), True)
+class DeficientNumbersTest(unittest.TestCase):
+    def test_smallest_prime_deficient_number(self):
+        self.assertIs(classify(2), "deficient")
 
-    def test_seventh_perfect_number(self):
-        self.assertIs(is_perfect(137438691328), True)
+    def test_smallest_nonprime_deficient_number(self):
+        self.assertIs(classify(4), "deficient")
+
+    def test_medium_deficient_number(self):
+        self.assertIs(classify(32), "deficient")
+
+    def test_large_deficient_number(self):
+        self.assertIs(classify(33550337), "deficient")
+
+    def test_edge_case(self):
+        self.assertIs(classify(1), "deficient")
+
+
+class InvalidInputsTest(unittest.TestCase):
+    def test_zero(self):
+        with self.assertRaises(ValueError):
+            classify(0)
+
+    def test_negative(self):
+        with self.assertRaises(ValueError):
+            classify(-1)
 
 
 if __name__ == '__main__':