如何读取CSV文件中的行，求和多少行 [英] How do I read lines in CSV file, sum a number of rows

问题描述

我使用c#，streamreader和writer格式化了此数据，并创建了这个csv文件.以下是示例数据:

A ------ BC ----- D ------------ E ------------ F ------- G-- ----- H --------- I
新C A123 08/24/2011 08/24/2011 100.00 100.00 X123456 276135
新C A125 08/24/2011 08/24/2011 200.00 100.00 X123456 276135
新C A127 08/24/2011 08/24/2011 50.00 100.00 X123456 276135
新T A122 08/24/2011 08/24/2011 5.00 100.00 X225511 276136
新T A124 08/24/2011 08/24/2011 10.00 100.00 X225511 276136
新T A133 08/24/2011 08/24/2011 500.00 100.00 X444556 276137

我想要以下输出:

新C A123 08/24/2011 08/24/2011 100.00 100.00 X123456 276135
新C A125 08/24/2011 08/24/2011 200.00 100.00 X123456 276135
新C A127 08/24/2011 08/24/2011 50.00 100.00 X123456 276135
新C A001 08/24/2011 08/24/2011 350.00 100.00 X123456 276135
新T A122 08/24/2011 08/24/2011 5.00 100.00 X225511 276136
新T A124 08/24/2011 08/24/2011 10.00 100.00 X225511 276136
新T A001 08/24/2011 08/24/2011 15.00 100.00 X225511 276136
新T A133 08/24/2011 08/24/2011 500.00 100.00 X444556 276137
新T A001 08/24/2011 08/24/2011 500.00 100.00 X225511 276137

对于字段"I"的每次更改，我想添加一行，对F列求和，在C中添加"A001"，然后复制内容
其他字段添加到该新添加的行中.列上的字母仅用于说明目的.没有标题.

首先，我应该先做什么?如何对F列求和，复制所有字段的内容，并向C添加"A001"?如何添加一行并复制带有I中每个更改的字段?

预先感谢您的帮助.

I formated this data using c#, streamreader and writer and created this csv file. Here is the sample data:

A------B-C-----D------------E------------F-------G-------H---------I
NEW C A123 08/24/2011 08/24/2011 100.00 100.00 X123456 276135
NEW C A125 08/24/2011 08/24/2011 200.00 100.00 X123456 276135
NEW C A127 08/24/2011 08/24/2011 50.00 100.00 X123456 276135
NEW T A122 08/24/2011 08/24/2011 5.00 100.00 X225511 276136
NEW T A124 08/24/2011 08/24/2011 10.00 100.00 X225511 276136
NEW T A133 08/24/2011 08/24/2011 500.00 100.00 X444556 276137

I would like the following output:

NEW C A123 08/24/2011 08/24/2011 100.00 100.00 X123456 276135
NEW C A125 08/24/2011 08/24/2011 200.00 100.00 X123456 276135
NEW C A127 08/24/2011 08/24/2011 50.00 100.00 X123456 276135
NEW C A001 08/24/2011 08/24/2011 350.00 100.00 X123456 276135
NEW T A122 08/24/2011 08/24/2011 5.00 100.00 X225511 276136
NEW T A124 08/24/2011 08/24/2011 10.00 100.00 X225511 276136
NEW T A001 08/24/2011 08/24/2011 15.00 100.00 X225511 276136
NEW T A133 08/24/2011 08/24/2011 500.00 100.00 X444556 276137
NEW T A001 08/24/2011 08/24/2011 500.00 100.00 X225511 276137

With each change in field "I", I would like to add a line, sum column F, add a "A001" to C, and copy the contents
of the other fields into that newly ADDed line. The letters on the columns are for illustrative purposes only. There are no headers.

First, what should I do first? How do I sum column F, copy contents of all fields, and add "A001" to C? How do I add a line and copy the fields w/ each change in I?

Thank you in advance for your help.

推荐答案

您的逗号是可视化的:-).我今天感觉很慷慨.请执行以下操作:

You commas are visualized :-). I feel pretty generous today. Do the following:

1. 创建代表一行(记录)的类或结构；我们称它为Record.
2. 使用这些记录的列表.从字面上看，添加:

1. Create a class or structure representing one line (record); let''s call it Record.
2. Use the list of those records. Literally, add:

using RecordList = System.Collections.Generic.List<Record>;

要读取文件，请使用System.IO.StreamReader；在"using"语句下创建它:

For reading a file, use System.IO.StreamReader; create it under "using" statement:

RecordList list = new RecordList();
using (System.IO.StreamReader reader = new System.IO.StreamReader(fileName) {
    //read lines here:
    string line = reader.ReadLine();
    //parse and validate each line
    Record record = //create instance of Record from parsed line
    list.Add(record);
} //at this point, reader.Dispose will be called automatically, even if an exception was thrown

写一种从记录中读取一行，对其进行解析和验证的方法. (上面显示为注释.)使用string.Split:
开始解析

Write a method of reading one line from a record, parsing and validating it. (It''s shown as a comment above.) Start parsing using string.Split:

//...
string[] values = line.Split(',', System.StringSplitOptions.RemoveEmptyEntries);
//convert strings into field of the type Record
//use DateTime.Parse, double.Parse, uint.Parse, etc. See appropriate MSDN help pages
//validate values as you parse
//for example:
record.F = double.Parse(values[5]); //may throw exception; decide how to handle it

要查找总和，请遍历列表，例如:

For finding sums, iterate through the list, for example:

double sumF = 0d;
/...
foreach (Record record in list) {
    sum.F += record.F;
    //...
}

如果您可能需要将数组用于其他目的，则上一步可能会显示为:

In case you might need an array for some other purposes, the previous step may look alternatively:

Record[] records = list.ToArray();
double sumF = 0d;
/...
foreach (Record record in records) {
    sum.F += record.F;
    //...
}

利润！

—SA

—SA

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