Convert class variables to instance variables

Using class variables is not necessary in this case.

taar/hbase_client.py

@@ -7,15 +7,16 @@
 class HBaseClient:
     _hostname = None
 
-    def __init__(self):
+    def __init__(self, hbase_hostname=None):
         self.tablename = 'main_summary'
         self.column_family = b'cf'
         self.column = b'cf:payload'
-        if HBaseClient._hostname is None:
-            HBaseClient._hostname = self._get_master_address()
-            print(HBaseClient._hostname)
+        if hbase_hostname is None:
+            self.hbase_hostname = self._get_hbase_hostname()
+        else:
+            self.hbase_hostname = hbase_hostname
 
-    def _get_master_address(self):
+    def _get_hbase_hostname(self):
         client = boto3.client('ec2')
         reservations = client.describe_instances(Filters=[
             {'Name': 'tag:Name', 'Values': ['telemetry-hbase']},
@@ -37,7 +38,7 @@ def get_client_profile(self, client_id):
         """Retrieve the latest row for the given client in HBase
 
         Only the last known version of the info is retrieved"""
-        with contextlib.closing(Connection(self._hostname)) as connection:
+        with contextlib.closing(Connection(self.hbase_hostname)) as connection:
             table = connection.table(self.tablename)
             row_start = "{}:{}".format(client_id, "99999999")
             for key, data in table.scan(row_start=row_start, limit=1,

taar/profile_fetcher.py

@@ -4,8 +4,11 @@
 class ProfileFetcher:
     """ Fetch the latest information for a client on HBase.
     """
-    def __init__(self):
-        self.hbase_client = HBaseClient()
+    def __init__(self, hbase_client=None):
+        if hbase_client is None:
+            self.hbase_client = HBaseClient()
+        else:
+            self.hbase_client = hbase_client
 
     def get(self, client_id):
         profile_data = self.hbase_client.get_client_profile(client_id)

taar/recommenders/recommendation_manager.py

@@ -9,31 +9,33 @@
 
 
 class RecommendationManager:
-    """
-    """
-    info_fetcher = None
-    recommenders = []
 
-    def __init__(self):
+    def __init__(self, profile_fetcher=None, recommenders=None):
         # Instantiate the object to get the client info.
-        if RecommendationManager.info_fetcher is None:
-            logger.info("Initializing info_fetcher")
-            RecommendationManager.info_fetcher = ProfileFetcher()
+        if profile_fetcher is None:
+            logger.info("Initializing profile_fetcher")
+            self.profile_fetcher = ProfileFetcher()
+        else:
+            self.profile_fetcher = profile_fetcher
 
         # Init the recommenders. Note: ORDER MATTERS!
         # The recommendation logic will go through each recommender and pick the
         # first one that "can_recommend".
-        if not RecommendationManager.recommenders:
+        if not recommenders:
             logger.info("Initializing recommenders")
-            RecommendationManager.recommenders.append(CollaborativeRecommender())
-            RecommendationManager.recommenders.append(LocaleRecommender())
-            RecommendationManager.recommenders.append(EmptyRecommender())
+            self.recommenders = (
+                CollaborativeRecommender(),
+                LocaleRecommender(),
+                EmptyRecommender()
+            )
+        else:
+            self.recommenders = recommenders
 
     def recommend(self, client_id, limit):
         # Get the info for the requested client id.
-        client_info = RecommendationManager.info_fetcher.get(client_id)
+        client_info = self.profile_fetcher.get(client_id)
 
         # Compute the recommendation.
-        for r in RecommendationManager.recommenders:
+        for r in self.recommenders:
             if r.can_recommend(client_info):
                 return r.recommend(client_info, limit)

tests/test_profile_fetcher.py

@@ -18,7 +18,7 @@ def test_profile_fetcher_returns_dict(monkeypatch):
                         get_client_profile_mock)
 
     monkeypatch.setattr(hbase_client.HBaseClient,
-                        '_get_master_address',
+                        '_get_hbase_hostname',
                         lambda x: 'master-ip-address')
 
     fetcher = ProfileFetcher()