Merge pull request #213 from ikostan/exercism-sync/727d223cc943f12e

[Sync Iteration] python/inventory-management/1

Author: ikostan

solutions/python/inventory-management/1/dicts.py

@@ -0,0 +1,76 @@
+"""Functions to keep track and alter inventory."""
+
+
+def create_inventory(items: list) -> dict:
+    """
+    Create a dict that tracks the amount (count) of each element
+    on the `items` list.
+
+    :param items: list - list of items to create an inventory from.
+    :return: dict - the inventory dictionary.
+    """
+    inventory: dict = {}
+    for item in items:
+        inventory[item] = items.count(item)
+    return inventory
+
+
+def add_items(inventory: dict, items: list) -> dict:
+    """
+    Add or increment items in inventory using elements from the items `list`.
+
+    :param inventory: dict - dictionary of existing inventory.
+    :param items: list - list of items to update the inventory with.
+    :return: dict - the inventory updated with the new items.
+    """
+    for item in set(items):
+        count: int = items.count(item)
+        if item in inventory:
+            inventory[item] += count
+        else:
+            inventory[item] = count
+    return inventory
+
+
+def decrement_items(inventory: dict, items: list) -> dict:
+    """
+    Decrement items in inventory using elements from the `items` list.
+
+    :param inventory: dict - inventory dictionary.
+    :param items: list - list of items to decrement from the inventory.
+    :return: dict - updated inventory with items decremented.
+    """
+    for item in set(items):
+        if item in inventory:
+            quantity: int = items.count(item)
+            if inventory[item] >= quantity:
+                inventory[item] -= quantity
+            else:
+                inventory[item] = 0
+    return inventory
+
+
+def remove_item(inventory: dict, item: str) -> dict:
+    """
+    Remove item from inventory if it matches `item` string.
+
+    :param inventory: dict - inventory dictionary.
+    :param item: str - item to remove from the inventory.
+    :return: dict - updated inventory with item removed.
+             Current inventory if item does not match.
+    """
+    if item in inventory:
+        inventory.pop(item)
+    return inventory
+
+
+def list_inventory(inventory: dict) -> list:
+    """
+    Create a list containing only available
+    (item_name, item_count > 0) pairs in inventory.
+
+    :param inventory: dict - an inventory dictionary.
+    :return: list of tuples - list of key, value pairs from the
+             inventory dictionary.
+    """
+    return [(key, inventory[key]) for key in inventory if inventory[key] != 0]