Add more functions to storage.py

- Add get_locations()
- Add init_location() to create a new blank location
- Add increment_amount() to increment the amount of one item
- Remove set_brand_key() since it will be replaced by separate functions
  for each property you can set

storage.py

@@ -28,10 +28,23 @@ def write_raw_json(writedict):
         print("Wrote dictionary as JSON to inventory.json")
 
 
+def get_locations():
+    return list(load_raw_json().keys())
+
+
 def get_items(location):
     return load_raw_json()[location]
 
 
+def init_location(location):
+    rawitems = load_raw_json()
+    if location not in rawitems.keys():
+        rawitems.update({location: {}})
+        write_raw_json(rawitems)
+    else:
+        raise AlreadyExistsError
+
+
 def init_item(location, item):
     rawitems = load_raw_json()
     if item not in rawitems[location].keys():
@@ -54,23 +67,16 @@ def init_brand(location, item, brand):
         raise AlreadyExistsError
 
 
-def set_brand_key(location, item, brand, key, value):
+def increment_amount(location, item, brand, amount):
     rawitems = load_raw_json()
-    if item not in rawitems[location].keys():
-        init_item(location, item)
-        rawitems = load_raw_json()
-
-    if brand not in rawitems[location][item].keys():
-        init_brand(location, item, brand)
-        rawitems = load_raw_json()
-
-    rawitems[location][item][brand].update({key: value})
+    newamt = rawitems[location][item][brand][amount] + int(amount)
+    rawitems[location][item][brand].update({"amount": newamt})
     write_raw_json(rawitems)
 
 
-def rm_brand_key(location, item, brand, key):
+def rm_brand_field(location, item, brand, field):
     rawitems = load_raw_json()
-    rawitems[location][item][brand].pop(key)
+    rawitems[location][item][brand].pop(field)
     write_raw_json(rawitems)