Develop Reference

Load text file data into data table for specific length scenario

I have a text file which has many irrelevant values and then have values which I have load it into a table. Sample of the file looks like this
Some file description date
C D 8989898989898 some words
D F 8979797979 some more words
8 H 98988989989898 Some more words for the purpose
KD978787878 280000841 1974DIAA EIDER 320
KK967867668 280000551 1999OOOD FIDERN 680
I can't start from the number of lines because the description part (which is 4 lines, excluding empty line) can be of multi line. Means, it can have up to 40-50 lines per text file.
The only way I can think to pick the data is to select only those rows which has 5 columns and have certain number of space between them.
I have tried it using foreach loop but that didn't work out pretty well. May be I am not able to implement it.
DataTable dt = new DataTable();
using (StreamWriter sw = File.CreateText(path))
{
string[] rows = content.Split('\n');
foreach (string s in rows)
{
// how to pick up rows when there are only 5 columns in a row separated by a definite number of space?
string[] columns = s.Split(' '); // how to calculate exact spaces here, because space count could be different from one column to the other. Ex: difference between first column and second is 16 and second to third is 8.
foreach (string t in columns)
{
}
}
}

A lot of this comes down to massaging and sanitizing the data(yuck!) I would:
1.Use String.Split on content to get all lines(like you did)
string[] lines = content.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.None);
2.Parse out empty lines and loop over the result
foreach(string line in lines.Where(x => !String.IsNullOrEmpty(x.Trim())))
3.Use String.Split on each line to split out each field for a particular row, stripping white space
string[] fields = line.Split(new string[] { " " }, StringSplitOptions.RemoveEmptyEntries);
At this point you can count the number of fields in the row or throw something at each actual field.

This is an ideal place to use regex to find only lines that fit your needs and even grouping them properly you can get out the trimmed values of the five columns already.
The search expressions seems to be something like "^(K[A-Z0-9]+) +([0-9]+) +([A-Z0-9]+) +([A-Z]+) +([0-9]+) *$" or similar. It helped me a lot in programming to know regex.

Issue renaming two columns in a CSV file instead of one

I need to be able to rename the column in a spreadsheet from 'idn_prod' to 'idn_prod1', but there are two columns with this name.
I have tried implementing code from similar posts, but I've only been able to update both columns. Below you'll find the code I have that just renames both columns.
//locate and edit column in csv
string file1 = #"C:\Users\username\Documents\AppDevProjects\import.csv";
string[] lines = System.IO.File.ReadAllLines(file1);
System.IO.StreamWriter sw = new System.IO.StreamWriter(file1);
foreach(string s in lines)
{
sw.WriteLine(s.Replace("idn_prod", "idn_prod1"));
}
I expect only the 2nd column to be renamed, but the actual output is that both are renamed.
Here are the first couple rows of the CSV:

I'm assuming that you only need to update the column header, the actual rows need not be updated.
var file1 = #"test.csv";
var lines = System.IO.File.ReadAllLines(file1);
var columnHeaders = lines[0];
var textToReplace = "idn_prod";
var newText = "idn_prod1";
var indexToReplace = columnHeaders
.LastIndexOf("idn_prod");//LastIndex ensures that you pick the second idn_prod
columnHeaders = columnHeaders
.Remove(indexToReplace,textToReplace.Length)
.Insert(indexToReplace, newText);//I'm removing the second idn_prod and replacing it with the updated value.
using (System.IO.StreamWriter sw = new System.IO.StreamWriter(file1))
{
sw.WriteLine(columnHeaders);
foreach (var str in lines.Skip(1))
{
sw.WriteLine(str);
}
sw.Flush();
}

Replace foreach(string s in lines) loop with
for loop and get the lines count and rename only the 2nd column.

I believe the only way to handle this properly is to crack the header line (first string that has column names) into individual parts, separated by commas or tabs or whatever, and run through the columns one at a time yourself.
Your loop would consider the first line from the file, use the Split function on the delimiter, and look for the column you're interested in:
bool headerSeen = false;
foreach (string s in lines)
{
if (!headerSeen)
{
// special: this is the header
string [] parts = s.Split("\t");
for (int i = 0; i < parts.Length; i++)
{
if (parts[i] == "idn_prod")
{
// only fix the *first* one seen
parts[i] = "idn_prod1";
break;
}
}
sw.WriteLine( string.Join("\t", parts));
headerSeen = true;
}
else
{
sw.WriteLine( s );
}
}
The only reason this is even remotely possible is that it's the header and not the individual lines; headers tend to be more predictable in format, and you worry less about quoting and fields that contain the delimiter, etc.
Trying this on the individual data lines will rarely work reliably: if your delimiter is a comma, what happens if an individual field contains a comma? Then you have to worry about quoting, and this enters all kinds of fun.
For doing any real CSV work in C#, it's really worth looking into a package that specializes in this, and I've been thrilled with CsvHelper from Josh Close. Highly recommended.

Calculating number of words from input text

I split the input paragraph by . and store it in an array like this:
string[] totalSentences = inputPara.Split('.')
then the function below is called which calculates total number of Words from each sentence like this:
public void initParaMatrix()
{
int size = 0;
for (int i = 0; i < totalSentences.Length; i++)
{
string[] words = totalSentences[i].Split();
size = size + words.Length;
//rest of the logic here...
}
matrixSize = size;
paraMatrix = new string[matrixSize, matrixSize];
}
paraMatrix is a 2D matrix equal to length of all words which I need to make in my logic.
The problem here is when I input only one sentence which has 5 words, the size variable gets the value 7. I tried the debugger and I was getting total of 2 sentences instead of 1.
Sentence 1. "Our present ideas about motion." > this is actual sentence which have only 5 words
Sentence 2. " " > this is the exact second sentence I'm getting.
Here is the screenshot:
Why I'm getting two sentences here and how is size getting value 7?

This makes perfect sense. If the second sentence has nothing but a " ", and you split along the " ", then you'll have two empty strings as a result. The easiest thing to do here is change the line you do the split, and add a trim:
string[] words = totalSentences[i].Trim().Split();
I don't know what version of Split that you're using since it accepts no parameters, but if you use String.Split you can set the second parameter so that empty entries are automatically removed by using the option StringSplitOptions.RemoveEmptyEntries.

You're not resetting the size integer to zero. So that's why you get 7 for the second sentence.
For the second sentence, which is a space, try inputPara.Trim() which should remove the space at the end of the string.

Split wrapped text into array

I want to split a string into an array at a point where the text wraps for a given width
Suppose this is the string.
I want text width to be 300 :
I want to split a string into an array at a point where the text wraps for a given width
And use a function, something like this :
Text.SplitAtWrap(300,Text)
This is the output i want :
(0) I want to split a string into an
(1) array at a point where the text
(2) wraps for a given width
Edit:
I would probably have to take the font into account, so probably have to use Drawing.Graphics.

There is an answer here (please give credit to whom deserve it)
public List<string> GetSubstrings(string toSplit, int maxLength, Graphics graph, Font font)
{
List<string> substrings = new List<string>();
string[] words = toSplit.Split(" ".ToCharArray());
string oneSub = "";
foreach (string oneWord in words)
{
string temp = oneSub + oneWord + " ";
if (graph.MeasureString( temp, font).Width > maxLength)
{
substrings.Add(oneSub);
oneSub = oneWord + " ";
}
else
oneSub = temp;
}
substrings.Add(oneSub);
return substrings;
}
Basically, your input string is divided in its component words, then each word is measured using the graphics object and a reference font. If the length of the current word plus the previous words is less than the required length the word is rejoined together. Otherwise the resulting string is added to a list of strings to be returned to the caller.

how to split a text in to paragraph with a particular string

I have a long text file ... I read the text file and store the content in a string...
Now I want this text to split. The below is an image which shows what I want.
In the image "This is common text" means this string is common in every paragraph.
Green squares shows that I want that part in string array.
but how o do that... I have tried Regular expression for this... but isn't working....
please help

Try using RegEx.Split() using this pattern:
(.*This is common text.*)
Well, giving priority to RegEx over the string functions is always leads to a performance overhead.
It would be great if you use: (UnTested but it will give you an idea)
string[] lines = IO.File.ReadAllLines("FilePath")
List<string> lst = new List<string>();
List<string> lstgroup = new List<string>();
int i=0;
foreach(string line in lines)
{
if(line.Tolower().contains("this is common text"))
{
if(i > 0)
{
lst.AddRange(lstgroup.ToArray());
// Print elements here
lstgroup.Clear();
}
else { i++; }
continue;
}
else
{
lstgroup.Add(line)
}
}
i = 0;
// Print elements here too

I am not sure what you want to split on but you could use
string[] stringArray = Regex.Split(yourString, regex);
If you want a more concrete example you will have to (as others mentioned) give us more information regardning what the text looks like rather than just "common text".