filehelpers-解析可变的行长 [英] filehelpers - Parsing variable line length

问题描述

我必须解析(C#)一个具有可变宽度和两行标题信息的.CSV文件(第一个是名称，第二个是单位).

数据如下:

Example1.CSV:

"timestamp","NAME_1","NAME_2","NAME_3","NAME_4"
"ms","unit_1","unit_2","unit_3","unit_4"
0.01,1.23,4.56,7.89,0.12
0.02,1.23,4.66,7.89,0.11
0.03,1.23,4.76,7.89,0.11
0.04,56.23,4.86,7.89,0.12

Example2.CSV:

"timestamp","NAME_1","NAME_2","NAME_3","NAME_4","NAME_5",...,"NAME_N"
"ms","unit_1","unit_2","unit_3","unit_4","unit_5",...,"unit_N"
0.01,1.23,4.56,7.89,0.12,0.13,...,0.27
0.02,1.23,4.66,7.89,0.12,0.13,...,0.22
0.03,1.23,4.76,7.89,0.11,0.13,...,0.24
0.04,56.23,4.86,7.89,0.12,0.13,...,0.29

以N为表格的宽度"(值最大为128或更大).我打算使用 Filehelpers .

我考虑过使用[FieldOptional()]-但这非常不方便，尤其是当宽度"可变时...

我当前的尝试看起来像

[IgnoreFirst(2)]
[DelimitedRecord(",")]
public sealed class LogData
{

    public Double ts;

    public Double Field1;

    [FieldNullValue(0.0)]
    [FieldOptional()]
    public Double Field2;

    [FieldNullValue(0.0)]
    [FieldOptional()]
    public Double Field3;

    // and so on
}

任何有关如何解决可变宽度"的帮助-以一种更加优雅的方式解决问题，我们将不胜感激-非常感谢！

本

解决方案

如果您打算将文件转换为DataTable，则有更好的选择

请使用FileHelpers库的CsvEngine.请参见下面的代码段:

using (MemoryStream stream = new MemoryStream(_fileContent)) //file content can be file as byte array
            {
                TextReader reader = new StreamReader(stream);
string path = "C:\\Sample.csv";
                CsvEngine csvEngine = new CsvEngine("Model", ',', path);
                var dataTable = csvEngine.ReadStreamAsDT(reader);
//Do whatever with dataTable

}

此处示例文件可以是csv文件，也可以是包含要处理的csv文件头的文本文件. DataTable的列将根据示例文件的标题命名

欢呼

I have to parse (C#) a .CSV file, with a variable "width" and 2 lines of header information (the fist one being name and the second one being the unit).

The data looks like:

Example1.CSV:

"timestamp","NAME_1","NAME_2","NAME_3","NAME_4"
"ms","unit_1","unit_2","unit_3","unit_4"
0.01,1.23,4.56,7.89,0.12
0.02,1.23,4.66,7.89,0.11
0.03,1.23,4.76,7.89,0.11
0.04,56.23,4.86,7.89,0.12

Example2.CSV:

"timestamp","NAME_1","NAME_2","NAME_3","NAME_4","NAME_5",...,"NAME_N"
"ms","unit_1","unit_2","unit_3","unit_4","unit_5",...,"unit_N"
0.01,1.23,4.56,7.89,0.12,0.13,...,0.27
0.02,1.23,4.66,7.89,0.12,0.13,...,0.22
0.03,1.23,4.76,7.89,0.11,0.13,...,0.24
0.04,56.23,4.86,7.89,0.12,0.13,...,0.29

With N being the "width" of the table (value can be up to 128 and larger). I'm planning to use Filehelpers.

I thought of using [FieldOptional()] - but that gets very unhandy, especially when the "width" is variable...

My current attempt looks like

[IgnoreFirst(2)]
[DelimitedRecord(",")]
public sealed class LogData
{

    public Double ts;

    public Double Field1;

    [FieldNullValue(0.0)]
    [FieldOptional()]
    public Double Field2;

    [FieldNullValue(0.0)]
    [FieldOptional()]
    public Double Field3;

    // and so on
}

Any help on "how to solve the variable width"-Problem in a more elegant manner is appreciated - Thank you very much in advance!

Ben

解决方案

If you are planning to convert the file into DataTable, there is a better option

Please use CsvEngine of FileHelpers library. See the code snippet below:

using (MemoryStream stream = new MemoryStream(_fileContent)) //file content can be file as byte array
            {
                TextReader reader = new StreamReader(stream);
string path = "C:\\Sample.csv";
                CsvEngine csvEngine = new CsvEngine("Model", ',', path);
                var dataTable = csvEngine.ReadStreamAsDT(reader);
//Do whatever with dataTable

}

Here the sample file can be csv file or text file contains the header of the csv file you want to process. The columns of the DataTable will be named according to the header of the sample file

Cheers

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