Question

我的商店程序代码有问题。如果用户在我的文件（products.csv）中输入了有效的GTIN-8号码，程序将运行正常。但是，如果用户输入了不在文件中的有效GTIN-8代码，则我的代码无效。

我想要打印'找不到代码'，然后重复该程序。目前，它只是“未找到”然后“你想购买多少”

我正在使用found = None，我很确定这是错误的但不确定要改变什么。

（参见checkfile功能）

def getproductcode():
    valid = False
    while not valid:
        code = input("Please enter the product code")
        valid = validatecode(code)
    return code

def validatecode(code):
    valid = False
    while True:
        if len(code) == 8:
            for i in code:
                try:
                    int(i)
                    valid = True
                except ValueError:
                    print("You have entered an invalid code type. Product codes are 8 numbers long. Please try again.")
                    return  False
            valid = checkvalidity(code)
            return valid
        else:
            print("You have entered an invalid code type. Product codes are 8 numbers long. Please try again.")
            return False

def checkvalidity(code):
        number = code
        total = int(number[0]) * 3 + int(number[1]) + int(number[2]) * 3 + int(number[3]) + int(number[4]) *3 + int(number[5]) + int(number[6]) * 3 + int(number[7])
        if total%10 == 0:
            check = 0
            print("Valid.")
            return True
        else:
            print("Invalid. Please try again.")
            return False
import csv

def checkfile(code):
    found = None # This seems redundant?
    with open('products.csv', 'r') as f:
        reader = csv.reader(f, delimiter=',')
        for line in reader:
            print(line) # To see what you're getting 
            if code == line[0]:
                print("We found your product ", code)
                return line
        print(code, "is not found. Please try again")

def quantityFunction():
    valid = False
    while True:
        quantity = input("Please enter the amount of this item you would like to purchase: ")
        for i in quantity:
            try:
                int(i)
                #repeat()
                return int(quantity)
            except ValueError:
                print("We didn't recognise that number. Please try again.")
                return int(quantity)

def repeat():
    print("Would you like to add another product?")
    print("1. Yes")
    repeatchoice = input("2. No")
    if repeatchoice == '1':
        return True
    elif repeatchoice == '2':
        return False
    else:
        print("We didn't recognise your choice. Please try again")
        repeat()

import datetime       
def append(product, quantity):

    f = open("reciepts","a")
    #time = str(datetime.datetime.now())
    #f.write(time)
    #for i in range(len(product)):
       #1 product 
     #   f.write(product[i])
    f.write(product)
    quantity = str(quantity)
    f.write(quantity)
    with open('products.csv', newline='') as f:
        reader = csv.reader(f, delimiter='\t')
        for line in f:
            print(line[1])

   # f.write(product)
    f.close


def reciept():
    print("Here is your reciept:")
    f = open("reciepts","r")
    print(f.read())
    #print("Here you are",f.readline())
    print("Thank you for shopping with Shoesmith's Home & Office Supplies Superstore. Please come again soon")
    print("Goodbye")

#rather than just print the file, read in each data to have decent formatting. i.e f.read data(1)



#main
f = open("reciepts","w")
f.write("")
f.close
repeatchoice = repeat()
repeatchoice == True
while repeatchoice == True:
    code = getproductcode()
    #print(code)
    product = checkfile(code)
    #print(product)
    quantity = quantityFunction()
    print(quantity)
    print(repeatchoice)
    addtoreciept = append(product, quantity)
    print(repeatchoice)
    repeatchoice = repeat()
    print(repeatchoice)
    #print(repeatchoice)
reciept()
#print(product, quantity)

'''with open('products.csv', newline='') as f:
        reader = csv.reader(f, delimiter='\t')
        for line in f:
            data = line.split(",")
            if code == data[0]:
                print("We found your product ",data)
                return data'''

我的csv看起来像这样;

34512340 Plain Brackets 0.5
12395675黄色卷笔刀2
56756777 100mm螺栓0.2
90673412 L形支架1.2

任何想法？感谢

Answer 1

首先，请尝试减少您在一个块中发布的代码量。从您的问题可以清楚地看出，您认为错误出现在checkfile函数中 - 请考虑粘贴该函数。

checkfile功能除了打印未找到代码外，如果有无效代码，则不会执行任何操作。特别是，它不会返回任何内容，这意味着它将返回None。在print语句之后放置你想要的任何行为。

声明found = None似乎毫无意义，除非found用于未粘贴的部分代码中。

Answer 2

它可能不是最有效的方式，但似乎有效......

我现在在我的几个函数中使用if product is not None:来阻止代码跳过quantityFunction。

替换找到=无？

2 个答案: