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Using LINQ to read delimited text files

By , 28 Mar 2010
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Did you ever face a situation where you want to read a delimited file (CSV or any similar format) and want to filter the records on the basis of some conditions (by checking some values against columns).
For example, let's assume that Data.txt file contains the following records:
If we want to find all records which belong to CityA with age >= 30 then we can use LINQ for this purpose:
string delimiter = ",;";
List<string> logs = (File.ReadAllLines(@"C:\Data.txt")
    // leave blank lines
    .Where(line => !string.IsNullOrEmpty(line))
    // split line seperated by delimiter
    .Select(line => line.Split(delimiter.ToCharArray(), StringSplitOptions.RemoveEmptyEntries))
    // compare the third column to find all records from CityA
    .Where(values => values[2].Equals("CityA", StringComparison.CurrentCultureIgnoreCase))
    // compare the second column to find all records with age more than or equal to 30
    .Where(values => int.Parse(values[1]) >= 30)
    // join back the splitted values by underscore
    .Select(values => string.Join("_", values))
    // find all unique values
    .ToList<string>());// convert to list
Hope this will help you out in reading delimited files Smile | :)


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About the Author

The Manoj Kumar
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India India

Manoj Kumar is a Humble Programmer and a trainer having dozens of trainings, publications and articles to his wallet.

His programming adventures began with Basic at an age of 11. Being a mathematician at core, soon he started looking for some more and moved to assembly language, later to C, C++, VC++ and finally to .Net.

He started his professional career as a VC++ 6 trainer, moved to embedded systems and device driver development, then to complex biological systems and finally moved to pure application development.

He has been teaching and training people for more than 12 years on a wide range of topics including Mathematics, Algorithms, Data Structures, C, C++, VC++, MFC, C#, Design Patterns and now a days he is working extensively with Visual Studio and .Net framework which includes VSX, WPF, Silverlight, WCF, WF, XAML and RIAs.


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Comments and Discussions

GeneralMy vote of 5 Pinmembernocturns229-Sep-13 12:16 
GeneralRe: My vote of 5 PinmemberThe Manoj Kumar15-Oct-13 17:29 
GeneralRe: My vote of 5 Pinmembernocturns216-Oct-13 11:10 
QuestionLine word‏ Pinmembererummirza30-Jul-13 17:24 
QuestionLine word Pinmembererummirza29-Jul-13 23:24 
AnswerRe: Line word PinmemberThe Manoj Kumar30-Jul-13 6:28 
GeneralRe: Line word Pinmembererummirza10-Aug-13 0:55 
GeneralMy vote of 5 PinmemberCarsten V2.012-Aug-12 4:50 
GeneralRe: My vote of 5 PinmemberThe Manoj Kumar1-Dec-12 20:12 
GeneralRe: My vote of 5 PinmemberCarsten V2.01-Dec-12 21:21 
GeneralReason for my vote of 5 good Pinmembervijay_dahite5-Aug-10 3:17 
GeneralRe: Reason for my vote of 5good PinmemberThe Manoj Kumar1-Dec-12 20:12 
GeneralReason for my vote of 5 good job~ Pinmemberpuyunhong14-Jul-10 21:13 
GeneralRe: Reason for my vote of 5good job~ PinmemberThe Manoj Kumar1-Dec-12 20:12 
GeneralNicely done! PinmemberRoger50015-Apr-10 13:52 
GeneralRe: Nicely done! PinmemberThe Manoj Kumar16-Apr-10 5:02 

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