Glasgow | 25 SDC NOV | Katarzyna Kazimierczuk | Sprint 2 | Lru cache

.gitignore

@@ -2,3 +2,4 @@
 node_modules
 .venv
 __pycache__
+package-lock.json

Sprint-2/implement_lru_cache/lru_cache.py

@@ -0,0 +1,50 @@
+import time
+from collections import OrderedDict
+
+class LruCache:
+    #  `LruCache(limit)` should construct 
+    # an LRU cache which never stores more than `limit` entries.
+    def __init__(self, user_limit):
+        self.limit = user_limit
+        self.our_list = OrderedDict()
+        self.lookup_map = {} 
+
+    # * `set(key, value)` should associate `value` with the passed `key`.
+    def set(self, key, value):
+
+        if key in self.lookup_map:
+            old_item = self.lookup_map[key]
+            self.our_list.pop(key)                
+        wrapped_item = {
+            "key": key,
+            "value": value,
+        }
+
+    #add to list and map
+        self.our_list[key] = wrapped_item
+        self.our_list.move_to_end(key, last=False)
+        self.lookup_map[key] = wrapped_item
+
+    #if full remove oldest timestamp so last
+        if len(self.our_list) > self.limit:
+            # oldest_item = self.our_list.pop() 
+
+            # del self.lookup_map[oldest_item["key"]]
+            oldest_key, oldest_item = self.our_list.popitem()
+            del self.lookup_map[oldest_key]
+
+    # * `get(key)` should look-up the value previously associated with `key`.
+    def get(self, key):
+    #check map instead of for loop    
+        if key in self.lookup_map:
+            # find by key
+            item = self.lookup_map[key]
+
+            #move to front
+            # self.our_list.remove(item)
+            # self.our_list.insert(0, item)
+            self.our_list.move_to_end(key, last=False)
+
+            return item["value"]
+        return None
+