Question

我有以下代码：

with open(s+ ".csv", mode='r') as f:
    reader = csv.reader(f)
    for row in reader:
        for gtin,currentstock in dictionary.items():
            #if row[0] in the file is equal to the key value in the dictionary...
            if row[0]==gtin:
                #Print the row for reference and...
                print(row)
                #Create a new list that would store the output (that is several rows)
                newdetails=[]
                line=row
                newdetails.append(line)
    #print all the rows (as a list of lists?) that are produced by the loop
    print("This prints only the last line...why?")
    print(newdetails)

输入为GTIN：12121212和GTIN 12345670（这些是存储在字典中的两个GTIN，我想在文件中查找）。

接下来我需要做两件事，非常感谢一些帮助。

如何存储循环结果（例如一系列行）？目前，只存储了由循环生成的满足条件的最后一行。
我需要使用新创建的（List？）来修改新创建的列表中的数据，使用字典中的VALUES（在这种情况下是当前股票）。同样，有多个值，所以有多个替换，我无法想到解决此问题的最佳方法。

输出如下：

  Want to update stock levels based on last order? - y/)y
  and here is my latest attempt.....
  ['12345670', 'Iphone 9.0', '500', '5', '3', '5']
  ['12121212', 'Samsung Laptop', '900', '5', '3', '5']
 This prints only the last line...why?
 [['12121212', 'Samsung Laptop', '900', '5', '3', '5']]

根据建议，我已经将newline = []排除在循环之外。但现在它做了更奇特的事情。它只打印文件中的最后一行（它不符合循环中设置的条件！）。

  with open(s+ ".csv", mode='r') as f:
        reader = csv.reader(f)
        for row in reader:
            for gtin,currentstock in dictionary.items():
                #if row[0] in the file is equal to the key value in the dictionary...
                if row[0]==gtin:
                        #Print the row for reference and...
                        print(row)
                        #Create a new list that would store the output (that is several rows)
        newdetails=[]
        line=row
        newdetails.append(line)

使用了相同的输入（首先打印的两个GTIN编号 - 这样位工作）。它创建了一个我需要帮助的新列表/答案。任何人吗？

以下（更改后）的输出：

['12345670', 'Iphone 9.0', '500', '5', '3', '5']
['12121212', 'Samsung Laptop', '900', '5', '3', '5']
 #This is now printing the last record in the FILE.
 [['9876545', 'Acer Allinone', '550', '5', '3', '5']]

我想要的是以某种格式存储前两行（与字典中的GTIN号匹配）（列表，我猜是吗？）。

谢谢你Jeon - 根据你的建议，我修改了代码并且它的工作原理 - 很近!!!

现在的代码是：

with open(s+ ".csv", mode='r') as f:
        newdetails=[]
        reader = csv.reader(f)

        for row in reader:

            for gtin,currentstock in dictionary.items():
                #if row[0] in the file is equal to the key value in the dictionary...
                if row[0]==gtin:
                        #Print the row for reference and...
                        print(row)
                        #Create a new list that would store the output (that is several rows)


                        line=row
                        newdetails.append(line)
    #print all the rows (as a list of lists?) that are produced by the loop
    print("?!?!?!??!?!")
    print(newdetails)

输出是仁慈的，我有点期待它：

['12345670', 'Iphone 9.0', '500', '5', '3', '5']
['12121212', 'Samsung Laptop', '900', '5', '3', '5']
?!?!?!??!?!
[['12345670', 'Iphone 9.0', '500', '5', '3', '5'], ['12121212', 'Samsung       Laptop', '900', '5', '3', '5']]

所以，现在我在列表中有一个列表。我真的很感激一些指导是如何通过查找字典中的值来替换这个列表列表（newdetails）。例如，

pseudocode:
if GTIN no matches index of list1 (in newdetails)
for that particular list(row), update the value of current stock, with the 
corresponding VALUE for the KEY(GTIN) in dictionary.

任何？ ....

如何在列表中存储从循环生成的行？（Python）的

0 个答案:

如何在列表中存储从循环生成的行？ （Python）的

0 个答案:

如何在列表中存储从循环生成的行？（Python）的