如何从csv文件读取特定行 [英] How to read particular rows from a csv file

问题描述

我的sample.csv文件如下所示:

ID名称Loc Sal
1 abc美国2342
2 xyz美国4567
3 QWE欧洲7864
4个空行
5 ASD欧洲4567

现在，我想将所有这些数据写入，但行包含loc作为"usa"到new.csv文件.在我的vb.net winform应用程序中，我编写了将所有行写入新文件的代码，但没有线索来过滤行.我不确定是否可以针对此问题使用相同的逻辑?有什么建议吗?

My sample.csv file looks like this:

ID Name Loc Sal
1 abc usa 2342
2 xyz usa 4567
3 qwe Europe 7864
4 empty row
5 asd Europe 4567

Now I want to write all this data except the rows contains loc as "usa" to new.csv file. In my vb.net winform application I coded for writing all the rows to a new file but haven''t got clue to filter the rows. I am not sure wether I can use same logic for this problem or not? Any suggestions please?

Dim ioFile As New System.IO.StreamReader("C:\sample.csv")
 Dim ioLine As String
 Dim ioLines As String
 ioLine = ioFile.ReadLine
 ioLines = "ID,Name,Number,Amount"
 ioLines &= vbCrLf & ioLine
 While Not ioLine = ""
    ioLine = ioFile.ReadLine
    ioLines = ioLines & vbCrLf & ioLine
 End While
 Dim ioWriter As New System.IO.StreamWriter("C:\new.csv")
 ioWriter.WriteLine(ioLines)
 ioFile.Close()
 ioWriter.Close()

推荐答案

您需要在该位置测试美国的每一行，我个人将使用split函数创建一个数组这样就可以知道您正在测试位置值，而在使用ioLine = ioFile.ReadLine
读取的行中的任何位置都找不到该值

You need to test each line for the USA in the location, I personally would use the split function to create an array so that you know you are testing the location value and not finding the value at any location in the line that you have read using ioLine = ioFile.ReadLine

while not ioLine = ""
  ioLine = ioFile.ReadLine
  dim Values as string() = ioLine.split(" ")
  if not values(2) = "usa" then
    iolines += system.environment.newline & ioline
  end if
end while

有关String.split的文档: String.split函数 [ ^ ]

Documentation on String.split: String.split function[^]

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