Python行为我无法理解

Question

我正在为学校做一个项目,需要在数据库(csv)中搜索产品.它通过将经过验证的EAN-8代码与每行的第0列匹配,在for循环中扫描来完成此操作.有一个尝试,除了试图匹配代码,然后显示产品,除非它找不到它,当它打算打印"产品未找到,再试".我尝试了不同的迭代if,else,if,elif结合尝试,除了但无济于事.请帮忙.

#code is the barcode
        for row in csv_file:
            try:
                if code == row[0]:
                    print("This product is: ", row[1], "\n", "Quantity left in stock: ", row[2], "\n", "Cost: ", row[3], "\n")
                    quant = int(input("How many do you you want?: "))
                    if quant > int(row[2]):
                        print("We don't have that many, try again")
                        order()
                    else:
                        orderrow = row
                        orderrow[2] = quant
                        orderrow[3] = float(orderrow[3]) * quant
                        totalcost = totalcost + orderrow[3]
                        orderlist.append(orderrow)


            except:
                print("ITEM NOT FOUND, TRY AGAIN")
                order()

Answer 1

你需要一个合适的if-else,而不是一个try-catch.这里没有Exception被抓住.怎么样:

for row in csv_file:
    if code == row[0]:
        print("This product is: ", row[1], "\n", "Quantity left in stock: ", row[2], "\n", "Cost: ", row[3], "\n")
        quant = int(input("How many do you you want?: "))
        if quant > int(row[2]):
            print("We don't have that many, try again")
            order()
        else:
            orderrow = row
            orderrow[2] = quant
            orderrow[3] = float(orderrow[3]) * quant
            totalcost = totalcost + orderrow[3]
            orderlist.append(orderrow)
    else:
        print("ITEM NOT FOUND, TRY AGAIN")
        order()