done

pyth

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+import csv 
+import sqlite3 
+class DatabaseConnector: 
+
+Manages a connection to a sqlite database. 
+
+def __init__(self, database_file): 
+self.connection = sqlite3.connect(database_file) 
+self.cursor = self.connection.cursor() 
+def populate(self, spreadsheet_folder): 
+""" 
+Populate the database with data imported from each spreadsheet. 
+""" 
+# open the spreadsheets 
+with open(f"{spreadsheet_folder}/shipping_data_0.csv", "r") as spreadsheet_file_0: 
+with open(f"{spreadsheet_folder}/shipping_data_1.csv", "r") as spreadsheet_file_1: 
+with open(f"{spreadsheet_folder}/shipping_data_2.csv", "r") as spreadsheet_file_2: 
+# prepare the csv readers 
+csv_reader_0 = csv.reader(spreadsheet_file_0) 
+csv_reader_1 = csv.reader(spreadsheet_file_1) 
+csv_reader_2 = csv.reader(spreadsheet_file_2) 
+# populate first spreadsheet 
+self.populate_first_shipping_data(csv_reader_0) 
+self.populate_second_shipping_data(csv_reader_1, csv_reader_2) 
+def populate_first_shipping_data(self, csv_reader_0): 
+""" 
+Populate the database with data imported from the first spreadsheet. 
+""" 
+for row_index, row in enumerate(csv_reader_0): 
+# ignore the header row 
+if row_index > 0: 
+# extract each required field 
+product_name = row[2] 
+product_quantity = row[4] 
+origin = row[0] 
+destination = row[1] 
+# insert the data into the database 
+self.insert_product_if_it_does_not_already_exist(product_name) 
+self.insert_shipment(product_name, product_quantity, origin, destination) 
+# give an indication of progress 
+print(f"inserted product {row_index} from shipping_data_0") 
+def populate_second_shipping_data(self, csv_reader_1, csv_reader_2): 
+""" 
+Populate the database with data imported from the second and third spreadsheets. 
+""" 
+# collect shipment info 
+shipment_info = {} 
+for row_index, row in enumerate(csv_reader_2): 
+# ignore the header row 
+if row_index > 0: 
+# extract each required field 
+shipment_identifier = row[0] 
+origin = row[1] 
+destination = row[2] 
+# store them for later use 
+shipment_info[shipment_identifier] = { 
+"origin": origin, 
+"destination": destination, 
+"products": {} 
+} 
+# read in product information 
+for row_index, row in enumerate(csv_reader_1): 
+# ignore the header row 
+if row_index > 0: 
+# extract each required field 
+shipment_identifier = row[0] 
+product_name = row[1] 
+# populate intermediary data structure 
+products = shipment_info[shipment_identifier]["products"] 
+if products.get(product_name, None) is None: 
+products[product_name] = 1 
+else: 
+products[product_name] += 1 
+# insert the data into the database 
+count = 0 
+for shipment_identifier, shipment in shipment_info.items(): 
+# collect origin and destination 
+origin = shipment_info[shipment_identifier]["origin"] 
+destination = shipment_info[shipment_identifier]["destination"] 
+for product_name, product_quantity in shipment["products"].items(): 
+# iterate through products and insert into database 
+self.insert_product_if_it_does_not_already_exist(product_name) 
+self.insert_shipment(product_name, product_quantity, origin, destination) 
+# give an indication of progress 
+print(f"inserted product {count} from shipping_data_1") 
+count += 1 
+def insert_product_if_it_does_not_already_exist(self, product_name): 
+""" 
+Insert a new product into the database. 
+If a product already exists in the database with the given name, 
+ignore it. 
+""" 
+query = """ 
+INSERT OR IGNORE INTO product (name) 
+VALUES (?); 
+""" 
+self.cursor.execute(query, (product_name,)) 
+self.connection.commit() 
+def insert_shipment(self, product_name, product_quantity, origin, destination): 
+""" 
+Insert a new shipment into the database. 
+""" 
+# collect the product id 
+query = """ 
+SELECT id 
+FROM product 
+WHERE product.name = ?; 
+""" 
+self.cursor.execute(query, (product_name,)) 
+product_id = self.cursor.fetchone()[0] 
+# insert the shipment 
+query = """ 
+INSERT OR IGNORE INTO shipment (product_id, quantity, origin, destination) 
+VALUES (?, ?, ?, ?); 
+""" 
+self.cursor.execute(query, (product_id, product_quantity, origin, destination)) 
+self.connection.commit() 
+def close(self): 
+self.connection.close() 
+if __name__ == '__main__': 
+database_connector = DatabaseConnector("shipment_database.db") 
+database_connector.populate("./data") 
+database_connector.close()