Extract data from text file - c#

I need to extract some data from a text file and insert to columns in excel sheet. I know how to do this if the rows and the length of the string is known.
try
{
using (System.IO.StreamReader sr = new System.IO.StreamReader("test.txt")
{
string line;
while ((line = sr.ReadLine()) != null)
{
listSNR.Items.Add(line.Substring (78,4));
}
}
}
But the particular text file is complex and the starting index or the length cannot be provided. But the starting word (PCPU01) of the row is known.
Eg: PCPU01,T2716,0.00,0.01,0.00,0.00
output:
T2716 0 0.01 0 0
In that case can somebody please let me know how to extract the texts?

using(System.IO.StreamReader sr = new System.IO.StreamReader("test.txt"))
{
string line;
while((line = sr.ReadLine()) != null)
{
string[] split = line.Split(',');
//...
}
}
split[0] will return "PCPU01", split[1] "T2716" and so on.

You can split one string into an array of strings, separated by a given character. This way, you could split the source string by a comma and use the resulting strings to build your output. Example:
string source = "PCPU01,T2716,0.00,0.01,0.00,0.00";
string[] parts = source.Split(',');
StringBuilder result = new StringBuilder();
result.Append(parts[1]); // The second element in the array, i.e. T2716
result.Append(" ");
result.Append(parts[2]); // 0.00
... // And so on...
return result.ToString() // return a string, not a StringBuilder

I hope this helps a little bit. You might have to tweak it to your needs. But this is a higher level code that gives you general idea of extracting data off a notepad.
DialogResult result = openFileDialog.ShowDialog();
Collection<Info> _infoCollection = new Collection<Info>();
Collection<string> listOfSubDomains = new Collection<string>();
string[] row;
string line;
// READ THE FILE AND STORE IT IN INFO OBJECT AND STORE TAHT INFO OBJECT IN COLLECTION
try
{
using (StreamReader reader = new StreamReader(openFileDialog.FileName))
{
while((line = reader.ReadLine()) != null)
{
Info _info = new Info();
row = line.Split(' ');
_info.FirstName = row[0];
_info.LastName = row[1];
_info.Email = row[2];
_info.Id = Convert.ToInt32(row[3]);
_infoCollection.Add(_info);
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message);
}

thanks for the answers. What i wanted is to identify the particular line in the text file and split the line into columns. So i was able to do this by calling a GetLine method:
string line15=GetLine(#"test.txt",15);
public string GetLine(string fileName, int line)
{
using (System.IO.StreamReader ssr = new System.IO.StreamReader("test.txt"))
//using (var ssr = new StreamReader("test.txt"))
{
for (int i = 1; i < line; i++)
ssr.ReadLine();
return ssr.ReadLine();
}
}
Then i splitted this line by using the delimiter (,)

This was my approach in C#. It takes a string input (which you can get out of a text file) and an int with which line you want to get. It then separates the string at a given seperator char to a list which in turn is then read out. If the given line number is lower than the count of the created list, the entry is given back.
public string GetLine(string multiline,int line)
{
List<string> lines = new List<string>();
lines = multiline.Split('\n').ToList<string>();
return lines.Count >= line ? lines[line] : "";
}

Related

StreamReader ReadLine() for CSV files

I am trying to use this code to create a list. It is failing at the NewCrime Convert step. Not sure how to use the stream reader. It is my first time and I usually use SQL so I have attempted to do the same thing I would do reading SQL here.
List MasterCrimeList;
public List<Crime.Crime> GetList()
{
MasterCrimeList = new List<Crime.Crime>();
try
{
string path = #"F:\\FanshaweCollegeClasses\\Winter2020\\CLAYS_FINAL_EXAM_2020\\VANHEESfinalEXAM\\SacramentocrimeJanuary2006.csv";
if (File.Exists(path))
{
// Open the file to read from.
using (StreamReader sr = File.OpenText(path))
{
string s;
while ((s = sr.ReadLine()) != null)
{
Crime.Crime NewCrime = new Crime.Crime(Convert.ToString(s[0]),//CrimeDateTime
Convert.ToString(s[1]),//CrimeAddress
Convert.ToInt32(Convert.ToString(s[2])),//CrimeDistrict
Convert.ToString(s[3]),//CrimeBeat
Convert.ToInt32(Convert.ToString(s[4])),//CrimeGrid
Convert.ToString(s[5]),//CrimeDescription
Convert.ToInt32(Convert.ToString(s[6])),//ncicCode
decimal.Parse(Convert.ToString(s[7])),//Latitude DECIMAL
decimal.Parse(Convert.ToString(s[8])));//Longitude DECIMAL
MasterCrimeList.Add(NewCrime);
}
}
}
}
When doing s[0] you're reading only one char of the whole line. What you should do is to split each line based on how the values are stored using Split(), and then you can access each value as an array. If it's a csv file:
string s;
while ((s = sr.ReadLine()) != null)
{
string[] lineValues = s.Split(new char[]{','});
string firstValue = lineValues[0];
string secondValue = lineValues[1];
...
}

Read file, check correctness of column, write file C#

I need to check certain columns of data to make sure there are no trailing blank spaces. At first thought I thought it would be very easy, but after attempting to achieve the goal I have got stuck.
I know that there should be 6-digits in the column I need to check. If there is less I will reject, if there are more I will trim the blank spaces. After doing that for the entire file, I want to write it back to the file with the same delimiters.
This is my attempt:
Everything seems to be working correctly except for writing the file.
if (File.Exists(filename))
{
using (StreamReader sr = new StreamReader(filename))
{
string lines = sr.ReadLine();
string[] delimit = lines.Split('|');
while (delimit[count] != "COLUMN_DATA_TO_CHANGE")
{
count++;
}
string[] allLines = File.ReadAllLines(#filename);
foreach(string nextLine in allLines.Skip(1)){
string[] tempLine = nextLine.Split('|');
if (tempLine[count].Length == 6)
{
checkColumn(tempLine);
writeFile(tempLine);
}
else if (tempLine[count].Length > 6)
{
tempLine[count] = tempLine[count].Trim();
checkColumn(tempLine);
}
else
{
throw new Exception("Not enough numbers");
}
}
}
}
}
public static void checkColumn(string[] str)
{
for (int i = 0; i < str[count].Length; i++)
{
char[] c = str[count].ToCharArray();
if (!Char.IsDigit(c[i]))
{
throw new Exception("A non-digit is contained in data");
}
}
}
public static void writeFile(string[] str)
{
string temp;
using (StreamWriter sw = new StreamWriter(filename+ "_tmp", false))
{
StringBuilder builder = new StringBuilder();
bool firstColumn = true;
foreach (string value in str)
{
if (!firstColumn)
{
builder.Append('|');
}
if (value.IndexOfAny(new char[] { '"', ',' }) != -1)
{
builder.AppendFormat("\"{0}\"", value.Replace("\"", "\"\""));
}
else
{
builder.Append(value);
}
firstColumn = false;
}
temp = builder.ToString();
sw.WriteLine(temp);
}
}
If there is a better way to go about this, I would love to hear it. Thank you for looking at the question.
edit:
file structure-
country| firstname| lastname| uniqueID (column I am checking)| address| etc
USA|John|Doe|123456 |5 main street|
notice the blank space after the 6
var oldLines = File.ReadAllLines(filePath):
var newLines = oldLines.Select(FixLine).ToArray();
File.WriteAllLines(filePath, newLines);
string FixLine(string oldLine)
{
string fixedLine = ....
return fixedLine;
}
The main problem with writing the file is that you're opening the output file for each output line, and you're opening it with append=false, which causes the file to be overwritten every time. A better approach would be to open the output file one time (probably right after validating the input file header).
Another problem is that you're opening the input file a second time with .ReadAllLines(). It would be better to read the existing file one line at a time in a loop.
Consider this modification:
using (StreamWriter sw = new StreamWriter(filename+ "_tmp", false))
{
string nextLine;
while ((nextLine = sr.ReadLine()) != null)
{
string[] tempLine = nextLine.Split('|');
...
writeFile(sw, tempLine);

How to incorporate a text qualifier in a file name used as a variable?

I have a C# script which takes in two CSV files as input, combines the two files, performs numerous calculations on them, and writes the result in a new CSV file.
These two input CSV file names are declared as variables and are used in the C# script by accessing those variable names.
The data in the input CSV files looks like this:
Since the data has values in thousands and millions, line splits in the C# code are truncating the data incorrectly. For instance a value of 11,861 appears only as 11 and 681 goes in the next columns.
Is there any way in C#, by which I can specify a text qualifier (" in this case) for the two files ?
Here is the C# code snippet:
string[,] filesToProcess = new string[2, 2] { {(String)Dts.Variables["csvFileNameUSD"].Value,"USD" }, {(String)Dts.Variables["csvFileNameCAD"].Value,"CAD" } };
string headline = "CustType,CategoryType,CategoryValue,DataType,Stock QTY,Stock Value,Floor QTY,Floor Value,Order Count,Currency";
string outPutFile = Dts.Variables["outputFile"].Value.ToString();
//Declare Output files to write to
FileStream sw = new System.IO.FileStream(outPutFile, System.IO.FileMode.Create);
StreamWriter w = new StreamWriter(sw);
w.WriteLine(headline);
//Loop Through the files one by one and write to output Files
for (int x = 0; x < filesToProcess.GetLength(1); x++)
{
if (System.IO.File.Exists(filesToProcess[x, 0]))
{
string categoryType = "";
string custType = "";
string dataType = "";
string categoryValue = "";
//Read the input file in memory and close after done
StreamReader sr = new StreamReader(filesToProcess[x, 0]);
string fileText = sr.ReadToEnd();
string[] lines = fileText.Split(Convert.ToString(System.Environment.NewLine).ToCharArray());
sr.Close();
where csvFileNameUSD and csvFileNameCAD are variables with values pointing to their locations.
Well, based on the questions you have answered, this ought to do what you want to do:
public void SomeMethodInYourCodeSnippet()
{
string[] lines;
using (StreamReader sr = new StreamReader(filesToProcess[x, 0]))
{
//Read the input file in memory and close after done
string fileText = sr.ReadToEnd();
lines = fileText.Split(Convert.ToString(System.Environment.NewLine).ToCharArray());
sr.Close(); // redundant due to using, but just to be safe...
}
foreach (var line in lines)
{
string[] columnValues = GetColumnValuesFromLine(line);
// Do whatever with your column values here...
}
}
private string[] GetColumnValuesFromLine(string line)
{
// Split on ","
var values = line.Split(new string [] {"\",\""}, StringSplitOptions.None);
if (values.Count() > 0)
{
// Trim leading double quote from first value
var firstValue = values[0];
if (firstValue.Length > 0)
values[0] = firstValue.Substring(1);
// Trim the trailing double quote from the last value
var lastValue = values[values.Length - 1];
if (lastValue.Length > 0)
values[values.Length - 1] = lastValue.Substring(0, lastValue.Length - 1);
}
return values;
}
Give that a try and let me know how it works!
You posted a very similar looking question few days ago. Did that solution not help you?
If so, what issues are you facing on that. We can probably help you troubleshoot that as well.

Read text file and split it over

So, I know my headline is a bit confusing, I will explain.
My code looks like this:
string filename = "C:\\C#\\maplist.txt"; // please put the text file path.
string filename2 = "C:\\C#\\zemaplist.txt";
string map;
StreamReader sr = new StreamReader(filename);
StreamWriter sw = new StreamWriter(filename2);
List<string> maps = new List<string> { };
while ((map = sr.ReadLine()) != null)
{
maps.Add(map);
}
sr.Close();
for (int i = 0; i < maps.Count; i++)
{
Console.WriteLine(maps[i]);
sw.WriteLine(maps[i]);
}
sw.Close();
and what i need to do is when the code read a new line, in my line there is
"Hey,Hey"
I want to split the , from each other so I can take both of them as other parameters, so that the first Hey will be added to maps and the other hey will be maps2,
How can I do that?
You can use Split() function to Split the given String based on delimiter.
Try This:
while ((map = sr.ReadLine()) != null)
{
maps.Add(map.Split(',')[0].Trim());
maps2.Add(map.Split(',')[1].Trim());
}
Simple Code:
using System.IO;
string filename = "C:\\C#\\maplist.txt"; // please put the text file path.
string filename2 = "C:\\C#\\zemaplist.txt";
string map;
StreamWriter sw = new StreamWriter(filename2);
List<string> maps = new List<string> { };
List<string> maps2 = new List<string> { };
String [] allLines = File.ReadAllLines(filename);
foreach(String line in allLines)
{
maps.Add(line.Split(',')[0].Trim());
maps2.Add(line.Split(',')[1].Trim());
}
for (int i = 0; i < maps.Count; i++)
{
Console.WriteLine(maps[i]);
sw.WriteLine(maps[i]);
}
sw.Close();
Solution 2:
String mapItem1="";
String mapItem2="";
if(maps.Count == maps2.Count)
{
for(int i=0;i<maps.Count;i++)
{
mapItem1=maps[i];
mapItem2=maps2[i];
}
}
while ((map = sr.ReadLine()) != null)
{
string[] split = map.Split(',');
//First Hey would be split[0], second Hey would be split[1]
maps.Add(split[0].Trim());
maps2.Add(split[1].Trim());
}
The Split method should help you out with that.
If you want to trim leading whitespace characters, you can use the .Trim() method on a string.
Use Split().
string heys = "Hey,Hey";
string[] splitArray = heys.Split(',');
Then you have:
splitArray[0] = "Hey";
splitArray[1] = "Hey";
Why even bother reading line by line? Read the entire file, replace the new line chars for a "," (to prevent last and first elements from different lines to be treated as one), and loop through a clean string.
string fileContent = Regex.Replace(File.ReadAllText("test.txt"), #"\r", ",");
List<string> mapList = new List<string>();
foreach (string map in Regex.Split(fileContent.Replace(#"\s+", ""), ","))
{
mapList.Add(map.Trim());
}

How to read values from a comma separated file?

I want to read words in a text file of a line separated by commas in c sharp.
For example, I want to read this line:
9/10/2011 10:05,995.4,998.8,995.4,997.5,118000
and get the values: 9/10/2011 10:05, 995.4, 998.8, 995.4, 997.5 and 118000.
Next, I also need to change the format of the date to MMddYYYY, and of the time to HHmmss (e.g. 100500).
I am using this code for reading is there anything wrong
private void button1_Click(object sender, EventArgs e)
{
StreamReader reader1 = File.OpenText(Path1);
string str = reader1.ReadToEnd();
reader1.Close();
reader1.Dispose();
// File.Delete(Path1);
string[] Strarray = str.Split(new char[] { Strings.ChrW(7) });
int abc = Strarray.Length - 1;
int xyz = 0;
bool status = true;
while (xyz <= abc)
{
try
{
status = true;
string[] strarray1 = Strarray[xyz].Split(",".ToCharArray());
string SecName = strarray1[0];
int a2 = 0;
while (status) //If the selected list is empty or the text file has selected name this will execute
{
status = false;
string SecSym = strarray1[1];
int DT = int.Parse(strarray1[2]);
int TM = int.Parse(strarray1[3]);
float O = float.Parse(strarray1[2]);
float H = float.Parse(strarray1[3]);
float L = float.Parse(strarray1[4]);
float C = float.Parse(strarray1[5]);
double OI = double.Parse(Convert.ToString(0));
float V = float.Parse(strarray1[6]);
// string a = string.Concat(SecName, ",",SecSym,",", DT, ",", TM, ",", O, ",", H, ",", L);
//writer.WriteLine(a);
}
}
catch
{ }
}
}
}
.Net comes with a ready CSV parser you can use to get your data. It's a part of VB.net, but you can easily use it in C# by adding a reference to the assembly Microsoft.VisualBasic (it's OK, honesly), and a using statement: using Microsoft.VisualBasic.FileIO;.
The code should be simple to understand:
List<String[]> fileContent = new List<string[]>();
using(FileStream reader = File.OpenRead(#"data.csv")) // mind the encoding - UTF8
using(TextFieldParser parser = new TextFieldParser(reader))
{
parser.TrimWhiteSpace = true; // if you want
parser.Delimiters = new[] { "," };
parser.HasFieldsEnclosedInQuotes = true;
while (!parser.EndOfData)
{
string[] line = parser.ReadFields();
fileContent.Add(line);
}
}
CSV is fairly simple, but it may contain quoted values with commas and newlines, so using Split isn't the best option.
Use the String.Split method to get an array of strings:
string[] ar = line.Split(',')
This should get you started.
using System;
using System.IO;
public class Sample
{
public static void Main() {
using (StreamReader reader = new StreamReader("yourfile.txt")) {
string line = null;
while (null != (line = reader.ReadLine())) {
string[] values = line.Split(',');
DateTime date = DateTime.Parse(values[0];
float[] numbers = new float[values.Length - 1];
for (int i = 1; i < values.Length - 1; i++)
numbers[i - 1] = float.Parse(values[i]);
// do stuff with date and numbers
}
}
}
}
I have also posted a simple CsvReader class which may be helpful for you.
For a quick and simple solution, you can stream through the file and parse each line using String.Split like this:
using (var sr = File.OpenText("myfile.csv"))
{
string line;
while ((line = sr.ReadLine()) != null)
{
var fields = line.Split(',');
var date = DateTime.Parse(fields[0].Trim());
var value1 = fields[0].Trim();
}
}
However, this appraoch if fairly error prone, for a more robust solution check out the CsvReader project, it's excellent for parsing CSV files like this. It will handle field values with commas, trimming spaces before and after fields, and much more.
If you need to parse a date string from a format not recognised by DateTime.Parse, try using DateTime.ParseExact instead.
For 1st part of your task use Split method with , as separator. To convert string datetime from one format to another you need to convert that string to datetime(DateTime.Parse, DateTime.ParseExact) and then convert to final format using DateTime.ToString method.
rows contain your output
StreamReader sStreamReader = new StreamReader("File Path");
string AllData = sStreamReader.ReadToEnd();
string[] rows = AllData.Split(",".ToCharArray());

Categories

Resources