From 4b6958de4a6a4872107a020d16c55faa70fa5fde Mon Sep 17 00:00:00 2001
From: brodriguez8774 <brodriguez8774@gmail.com>
Date: Sun, 22 Sep 2019 22:32:22 -0400
Subject: [PATCH] Implement methods to give knapsack class the initial data
---
resources/knapsack.py | 41 ++++++++++++++++++++++-
tests/resources/knapsack.py | 66 +++++++++++++++++++++++++++++++++++++
2 files changed, 106 insertions(+), 1 deletion(-)
diff --git a/resources/knapsack.py b/resources/knapsack.py
index a06b84c..a2329d7 100644
--- a/resources/knapsack.py
+++ b/resources/knapsack.py
@@ -25,4 +25,43 @@ class Knapsack():
Knapsack algorithm.
"""
def __init__(self):
- pass
+ self._item_set_ = None
+ self._max_weight_ = None
+
+ def set_item_set(self, item_set):
+ """
+ Sets group of items to choose from.
+ :param item_set: Set of items, essentially in JSON format.
+ """
+ # Check that value is List type.
+ if not isinstance(item_set, list):
+ raise TypeError('Arg must be array of dict objects.')
+
+ # Check all items in item set.
+ for item in item_set:
+ # Check that array values are Dict type.
+ if not isinstance(item, dict):
+ raise TypeError('Arg must be array of dict objects.')
+
+ if 'benefit' not in item.keys():
+ raise KeyError('Key "benefit" must be present in all items.')
+
+ if 'cost' not in item.keys():
+ raise KeyError('Key "cost" must be present in all items.')
+
+ self._item_set_ = item_set
+
+ def set_max_weight(self, max_weight):
+ """
+ Sets upper bound to limit algorithm choices.
+ :param max_weight: Upper bound of algorithm's "bag".
+ """
+ # Check that value is an Int.
+ if not isinstance(max_weight, int):
+ raise TypeError('Arg must be of type Int.')
+
+ # Check that value is greater than 0.
+ if max_weight <= 0:
+ raise ValueError('Arg must be greater than 0.')
+
+ self._max_weight_ = max_weight
diff --git a/tests/resources/knapsack.py b/tests/resources/knapsack.py
index 61a4b9b..3ba9d20 100644
--- a/tests/resources/knapsack.py
+++ b/tests/resources/knapsack.py
@@ -19,5 +19,71 @@ class TestKnapsack(unittest.TestCase):
def setUp(self):
self.knapsack = Knapsack()
+ self.item_set_1 = [
+ {
+ 'benefit': 12,
+ 'cost': 4
+ },
+ {
+ 'benefit': 32,
+ 'cost': 8
+ },
+ {
+ 'benefit': 40,
+ 'cost': 2
+ },
+ {
+ 'benefit': 30,
+ 'cost': 6
+ },
+ {
+ 'benefit': 50,
+ 'cost': 1
+ }
+ ]
+
def test_knapsack_creation(self):
self.assertTrue(isinstance(self.knapsack, Knapsack))
+
+ def test_set_item_set_success(self):
+ self.knapsack.set_item_set(self.item_set_1)
+ self.assertEqual(self.knapsack._item_set_, self.item_set_1)
+
+ def test_set_item_set_failure(self):
+ with self.subTest('Arg is not array of dicts'):
+ with self.assertRaises(TypeError):
+ self.knapsack.set_item_set(None)
+
+ with self.assertRaises(TypeError):
+ self.knapsack.set_item_set([1, 2, 3])
+
+ with self.subTest('Dict item must have "benefit" and "cost" keys.'):
+ with self.assertRaises(KeyError):
+ self.knapsack.set_item_set([{'benefit': 1}])
+
+ with self.assertRaises(KeyError):
+ self.knapsack.set_item_set([{'cost': 1}])
+
+ def test_set_max_weight_success(self):
+ self.knapsack.set_max_weight(1)
+ self.assertEqual(self.knapsack._max_weight_, 1)
+
+ self.knapsack.set_max_weight(2)
+ self.assertEqual(self.knapsack._max_weight_, 2)
+
+ def test_set_max_weight_failure(self):
+ with self.subTest('Arg is not of type Int'):
+ with self.assertRaises(TypeError):
+ self.knapsack.set_max_weight(None)
+
+ with self.assertRaises(TypeError):
+ self.knapsack.set_max_weight('Test')
+
+ with self.subTest('Arg is not greater than 0'):
+ with self.assertRaises(ValueError):
+ self.knapsack.set_max_weight(0)
+
+ with self.assertRaises(ValueError):
+ self.knapsack.set_max_weight(-1)
+
+
--
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