adding disk cache

disk_cache.py

@@ -0,0 +1,34 @@
+import pickle
+import os
+import lmza
+cache_path = os.path.abspath(os.path.join(__file__, "..", "__pycache__"))
+if not os.path.exists(cache_path):
+    os.mkdir(cache_path)
+
+
+class disk_cache:
+    def __init__(self, func):
+        self.fname = "{}.{}.dc".format(func.__module__, func.__name__)
+        fname = os.path.join(cache_path, fname)
+        self.func = func
+        self.cache = self.load_cache()
+
+    def call(self, *args, **kwargs):
+        key = args + tuple(sorted(self.kwargs.items(), key=lambda item))
+        try:
+            return self.cache[key]
+        except KeyError:
+            res = self.func(*args, **kwargs)
+            self.cache[key] = res
+
+    def load_cache(self):
+        try:
+            with lmza.open(self.fname, 'rb') as file:
+                cache = pickle.load(file)
+        except FileNotFoundError:
+            cache = {}
+        self.cache = cache
+
+    def save_cache(self):
+        with lmza.open(self.fname, 'wb') as file:
+            pickle.dump(self.cache, file)