'Solution'

app/main.py

@@ -1 +1,24 @@
-# write your code here
+import csv
+
+
+def create_report(data_file_name: str, report_file_name: str) -> None:
+    with open(data_file_name, "r") as data_file:
+        reader = csv.reader(data_file)
+        total_buy = 0
+        total_supply = 0
+        for row in reader:
+            if not row:
+                continue
+            operation_type,amount = row[0], int(row[1])
+            if operation_type == "supply":
+                total_supply += amount
+            if operation_type == "buy":
+                total_buy += amount
+
+        result = total_supply - total_buy
+
+    with open(report_file_name, "w", newline="") as report_file:
+        writer = csv.writer(report_file)
+        writer.writerow(["supply",total_supply])
+        writer.writerow(["buy", total_buy])
+        writer.writerow(["result", result])

apples.csv

@@ -1,11 +1,11 @@
-supply,30
-buy,10
-buy,13
-supply,17
-buy,10
-supply,5
-supply,80
-buy,39
-supply,56
-buy,32
-buy,11
+supply,30
+buy,10
+buy,13
+supply,17
+buy,10
+supply,5
+supply,80
+buy,39
+supply,56
+buy,32
+buy,11

bananas.csv

@@ -1,15 +1,15 @@
-buy,10
-supply,300
-buy,130
-buy,12
-supply,20
-buy,1
-supply,50
-supply,12
-supply,8
-buy,41
-supply,10
-buy,12
-buy,10
-buy,77
-supply,91
+buy,10
+supply,300
+buy,130
+buy,12
+supply,20
+buy,1
+supply,50
+supply,12
+supply,8
+buy,41
+supply,10
+buy,12
+buy,10
+buy,77
+supply,91

grapes.csv

@@ -1,13 +1,13 @@
-supply,78
-buy,9
-buy,17
-buy,22
-supply,27
-buy,80
-supply,51
-supply,82
-buy,49
-supply,102
-supply,12
-buy,29
-buy,146
+supply,78
+buy,9
+buy,17
+buy,22
+supply,27
+buy,80
+supply,51
+supply,82
+buy,49
+supply,102
+supply,12
+buy,29
+buy,146

oranges.csv

@@ -1,11 +1,11 @@
-buy,19
-supply,33
-buy,37
-supply,170
-buy,80
-supply,44
-supply,31
-buy,3
-supply,17
-buy,6
-buy,9
+buy,19
+supply,33
+buy,37
+supply,170
+buy,80
+supply,44
+supply,31
+buy,3
+supply,17
+buy,6
+buy,9