Merge pull request #113 from dbt-labs/fix/order-total-rounding-errors

Fix order total rounding errors in output

jafgen/customers/order.py

@@ -23,11 +23,13 @@ def to_dict(self) -> dict[str, Any]:
             "id": self.order_id,
             "customer": self.customer.customer_id,
             "ordered_at": self.day.date.isoformat(),
-            # "order_month": self.day.date.strftime("%Y-%m"),
             "store_id": self.store.store_id,
             "subtotal": int(self.subtotal * 100),
             "tax_paid": int(self.tax_paid * 100),
-            "order_total": int(self.order_total * 100),
+            # TODO: figure out why this is doesn't cause a test failure
+            # in tests/test_order_totals.py
+            # "order_total": int(self.order_total * 100),
+            "order_total": int(int(self.subtotal * 100) + int(self.tax_paid * 100)),
         }
 
     def items_to_dict(self) -> list[dict[str, Any]]:

jafgen/simulation.py

@@ -1,7 +1,7 @@
+import csv
 import os
 import uuid
 
-import pandas as pd
 from rich.progress import track
 
 from jafgen.curves import Day
@@ -114,30 +114,23 @@ def run_simulation(self):
     def save_results(self) -> None:
         stock: Stock = Stock()
         inventory: Inventory = Inventory()
-        entities: dict[str, pd.DataFrame] = {
-            "customers": pd.DataFrame.from_records(
-                [customer.to_dict() for customer in self.customers.values()]
-            ),
-            "orders": pd.DataFrame.from_records(
-                [order.to_dict() for order in self.orders]
-            ),
-            "items": pd.DataFrame.from_records(
-                [item.to_dict() for order in self.orders for item in order.items]
-            ),
-            "stores": pd.DataFrame.from_records(
-                [market.store.to_dict() for market in self.markets]
-            ),
-            "supplies": pd.DataFrame.from_records(stock.to_dict()),
-            "products": pd.DataFrame.from_records(inventory.to_dict()),
+        entities: dict[str, list[dict]] = {
+            "customers": [customer.to_dict() for customer in self.customers.values()],
+            "orders": [order.to_dict() for order in self.orders],
+            "items": [item.to_dict() for order in self.orders for item in order.items],
+            "stores": [market.store.to_dict() for market in self.markets],
+            "supplies": stock.to_dict(),
+            "products": inventory.to_dict(),
         }
+
         if not os.path.exists("./jaffle-data"):
             os.makedirs("./jaffle-data")
-        # save output
-        for entity, df in track(
+        for entity, data in track(
             entities.items(), description="🚚 Delivering jaffles..."
         ):
-            df.to_csv(
-                f"./jaffle-data/{self.prefix}_{entity}.csv",
-                header=df.columns.to_list(),
-                index=False,
-            )
+            with open(
+                f"./jaffle-data/{self.prefix}_{entity}.csv", "w", newline=""
+            ) as file:
+                writer = csv.DictWriter(file, fieldnames=data[0].keys())
+                writer.writeheader()
+                writer.writerows(data)

requirements.in

@@ -1,4 +1,3 @@
 numpy
-pandas
 Faker
-typer[all]
+typer

requirements.txt

@@ -2,32 +2,22 @@
 #    uv pip compile requirements.in -o requirements.txt
 click==8.1.7
     # via typer
-colorama==0.4.6
-    # via typer
-faker==24.4.0
+faker==24.7.1
 markdown-it-py==3.0.0
     # via rich
 mdurl==0.1.2
     # via markdown-it-py
 numpy==1.26.4
-    # via pandas
-pandas==2.2.1
 pygments==2.17.2
     # via rich
 python-dateutil==2.9.0.post0
-    # via
-    #   faker
-    #   pandas
-pytz==2024.1
-    # via pandas
+    # via faker
 rich==13.7.1
     # via typer
 shellingham==1.5.4
     # via typer
 six==1.16.0
     # via python-dateutil
-typer==0.10.0
-typing-extensions==4.10.0
+typer==0.12.2
+typing-extensions==4.11.0
     # via typer
-tzdata==2024.1
-    # via pandas

tests/test_order_totals.py

@@ -1,7 +1,7 @@
 from jafgen.customers.order import Order
 from jafgen.curves import Day
 from jafgen.stores.store import Store
-from jafgen.customers.customers import RemoteWorker
+from jafgen.customers.customers import RemoteWorker, BrunchCrowd, Student
 from jafgen.stores.inventory import Inventory
 
 
@@ -18,15 +18,49 @@ def test_order_totals():
                 items=[
                     inventory.get_food()[0],
                     inventory.get_drink()[0],
+                    inventory.get_food()[0],
+                ],
+                store=store,
+                day=Day(date_index=i),
+            )
+        )
+        orders.append(
+            Order(
+                customer=BrunchCrowd(store=store),
+                items=[
+                    inventory.get_food()[0],
+                    inventory.get_drink()[0],
+                    inventory.get_food()[0],
+                ],
+                store=store,
+                day=Day(date_index=i),
+            )
+        )
+        orders.append(
+            Order(
+                customer=Student(store=store),
+                items=[
+                    inventory.get_food()[0],
+                    inventory.get_drink()[0],
+                    inventory.get_food()[0],
                 ],
                 store=store,
                 day=Day(date_index=i),
             )
         )
     for order in orders:
-        assert order.subtotal == order.items[0].item.price + order.items[1].item.price
+        assert (
+            order.subtotal
+            == order.items[0].item.price
+            + order.items[1].item.price
+            + order.items[2].item.price
+        )
         assert order.tax_paid == order.subtotal * order.store.tax_rate
         assert order.order_total == order.subtotal + order.tax_paid
         assert round(float(order.order_total), 2) == round(
             float(order.subtotal), 2
         ) + round(float(order.tax_paid), 2)
+        order_dict = order.to_dict()
+        assert (
+            order_dict["order_total"] == order_dict["subtotal"] + order_dict["tax_paid"]
+        )