在Python中满足条件时如何将文本文件中的数字与字符串相加

Question

我正在做一个库存系统，要求我打印特定物品的分销清单。如果某一商品已分发到同一家商店超过一次，它需要将数量相加在一起。

我不允许使用字典和熊猫。只能使用列表

项需要使用代码进行搜索

交易文本文件：

S001，T01，T恤，4

S001，T01，T恤，7

S002，T02，鞋，9岁

S003，T02，鞋子，11岁

第一个是商店代码，第二个是商品代码，然后是商品名称和分配数量。

这是我的密码

x=open("transactions.txt","r")
numbers = []
total = 0
searchInput=input("Enter item code to search: ")
for line in x:
      lines = line.strip()
      s = lines.split(",")
      numbers.append(s)
      if not searchInput.lower() in lines.lower():
            continue
      column = -1
      record = len(numbers)
      for v in range(record):
            if searchInput == s[1]:
                  column = v
      if ((numbers[column][0] == numbers[column][0]) and (numbers[column][1] == numbers[column][1])):
            num = int(numbers[column][-1])
            total += num
if column >=0:
      a=numbers[column][0]+","+numbers[column][1]+","+numbers[column][2]+","+str(total)
      print(a)

当我输入T01 for searchInput时，它可以用最新的总数正确地打印。但是当我在T02中输入时，它会总结我的总数，即使是商店代码也是不同的。它应该打印2行T02，而不加起来。

当我输入T02 for searchInput时，输出应该如下所示

S002，T02，鞋，9岁

S003，T02，鞋子，11岁

Answer 1

我已经尝试过猜测您的具体用例，所以我的示例可能有点错误。首先，让我介绍一下您的一些代码，并给出我的一些评论：

numbers = []
total = 0
x = open("transactions.txt","r")

for line in x:

    print(line)

    lines = line.strip()
    s = lines.split(",")

    numbers.append(s)
    print(numbers)

    if not searchInput.lower() in lines.lower():
        # keep only the lines which have a match with the search input
        continue

    column = -1
    record = len(numbers)
    print(f'len(numbers): {len(numbers)}')

    for v in range(record):
        # 
        if searchInput == s[2]:
            # s is the current line, 2 denotes the 3rd entry e.g. the item
            # column will be overwritten by v as long as searchInput matches s[2] exactly
            # column will therefore be equal to len(numbers)-1
            column = v
            print(f'column: {column}')

    if ((numbers[column][0] == numbers[column][0]) and (numbers[column][1] == numbers[column][1])):
        # if one item equals itself, and another item equals itself, then:
        # num is the integer of last value in the column record
        num = int(numbers[column][-1])
        total += num

请注意输出是如何不清楚的。使用Python的关键特性之一是保持代码清晰易读，因此当其他人(或您未来的自我)返回到此代码时，您可以从您离开的地方开始。

基于您所告诉的，我尝试以以下方式重新编写您的代码。请特别注意变量的命名。请注意，此示例是一个非常基本的示例，如果您处理输入数据，您可能需要在其中包装一些try-除了语句和错误处理。当然，您也可以决定切换到其他库，比如csv，因为您已经有了一个逗号分隔的值，甚至可以在其中进行熊猫，为这些列命名以便于阅读，甚至添加日期时列，这样就可以过滤日期。不管怎么说，我认为你想达到的目标是：

searchInput = input("Enter item code to search: ").lower()

records = list()
transactions = open("transactions.txt","r")

for record in transactions:
    # cleaning the record by stripping leading and trailing spaces, lowering cases and splitting on the commas
    clean_record = record.strip().lower().split(',')

    if any([searchInput in x for x in clean_record]):
        # keep only the lines which have a match with the search input
        records.append(clean_record)

total = dict()
for record in records:
    # now that we have all the records we want
    # we will retrieve the relevant information
    # we want a the sum of the values, printed for each store
    if record[0] not in total.keys():
        total[record[0]] = int(record[-1])
    else:
        total[record[0]] += int(record[-1])

for shop, tot in total.items():
    print(f'Shop: {shop} - Total: {tot}')