在 Python 中从数据库中的项目添加总计

Question

我想编写一个代码来创建一个

while True

循环并要求用户从显示的杂货列表中选择一个或多个项目。当用户完成后，我想跳出循环，计算这些商品的总价并将其打印到屏幕上。

import sqlite3
connection = sqlite3.connect('seasonalProduce.db')
cursor = connection.cursor()
cursor.execute("""CREATE TABLE IF NOT EXISTS productList (
     productID integer PRIMARY KEY,
     productName text NOT NULL,
     productPrice real
);""")



#add rows (records) to the productList table

productRecords = [(1, "Apples", 4.59),
            (2, "Grapes", 5.99),
            (3, "Pumpkin", 3.00),
            (4, "Strawberries", 2.50),
            (5, "Leafy Greens", 4.00)]
            
cursor.executemany("INSERT OR IGNORE INTO productList (productID, productName, productPrice) VALUES(?,?,?);", productRecords)

connection.commit()

cursor.execute("SELECT * FROM productList;")

produce = cursor.fetchall()

for rows in produce:
print(rows)

connection.close()


while True:
    while True:
        try:
        choice1 = input("Please enter the product ID number:")
        if choice1 in range(8):
            print("Thank you. Please enter the price of the item.")
            price1 = input(float("price per kg:"))
            break
        else:
            print("Please try again. Enter a number within range 1 to 7.")
    except ValueError:
        print("Invalid input. Please try again.")

        while True:
            choice2 = input("Please enter the product ID number:")
            if choice2 in range(8):
                print("Thank you.Please enter the price of the item.")
                price1 = input(float("price per kg:"))
                price2 = input(float("price per kg:"))
                break
            else:
                print("Please try again. Enter a number within range 1 to 7.")
    try:
        userContinue = input("Would you like to add another item to your purchase? Y/N: ")
        if userContinue.upper() == "Y":
            choice3 = input("Please enter the product ID number:")
        elif userContinue.upper() == "N":
            total = price1 + price2
            print("Your total is", total)
    except ValueError:
        print("Invalid input. Please try again.")`

Answer 1

代码中有一些错误。当你执行迭代时，有很多缩进错误。 while 和 try 语句以及缩进错误导致了程序中的大量冲突。因此必须将其删除。另一个问题是在选择输入之后的 if 语句中。在继续之前，我们必须将字符串转换为整数。分别从字符串转换重量。最后，如果用户输入 3 个产品，代码不会添加并显示总和。这是更正所有问题后的代码，它应该可以顺利运行：

import sqlite3
connection = sqlite3.connect('seasonalProduce.db')
cursor = connection.cursor()
cursor.execute("""CREATE TABLE IF NOT EXISTS productList (
     productID integer PRIMARY KEY,
     productName text NOT NULL,
     productPrice real
);""")



#add rows (records) to the productList table

productRecords = [(1, "Apples", 4.59),
            (2, "Grapes", 5.99),
            (3, "Pumpkin", 3.00),
            (4, "Strawberries", 2.50),
            (5, "Leafy Greens", 4.00)]
            
cursor.executemany("INSERT OR IGNORE INTO productList (productID, productName, productPrice) VALUES(?,?,?);", productRecords)

connection.commit()


cursor.execute("SELECT * FROM productList;")

produce = cursor.fetchall()

for rows in produce:
    print(rows)

connection.close()

choice1 = input("Please enter the product ID number:")
if int(choice1) in range(8):
    print("Thank you. Please enter the price of the item.")
    price1 = input("price per kg:")
    float_price1=float(price1)
else:
    print("Please try again. Enter a number within range 1 to 7.")
choice2 = input("Please enter the product ID number:")
if int(choice2) in range(8):
    print("Thank you.Please enter the price of the item.")
    price2 = input("price per kg:")
    float_price2=float(price2)
else:
    print("Please try again. Enter a number within range 1 to 7.")
userContinue = input("Would you like to add another item to your purchase? Y/N: ")
if userContinue.upper() == "Y":
    choice3 = input("Please enter the product ID number:")
    if int(choice2) in range(8):
        print("Thank you.Please enter the price of the item.")
        price3 = input("price per kg:")
        float_price3=float(price3)
        print("Your total is", float_price1+float_price2+float_price3)
elif userContinue.upper() == "N":
    total = price1 + price2
    print("Your total is", total)