Develop Reference

Make every other a-z letter Upper / Lower case, ignoring whitespace

Can somebody tell me what I am doing wrong please? can't seem to get the expected output, i.e. ignore whitespace and only upper/lowercase a-z characters regardless of the number of whitespace characters
my code:
var sentence = "dancing sentence";
var charSentence = sentence.ToCharArray();
var rs = "";
for (var i = 0; i < charSentence.Length; i++)
{
if (charSentence[i] != ' ')
{
if (i % 2 == 0 && charSentence[i] != ' ')
{
rs += charSentence[i].ToString().ToUpper();
}
else if (i % 2 == 1 && charSentence[i] != ' ')
{
rs += sentence[i].ToString().ToLower();
}
}
else
{
rs += " ";
}
}
Console.WriteLine(rs);
Expected output: DaNcInG sEnTeNcE
Actual output: DaNcInG SeNtEnCe

I use flag instead of i because (as you mentioned) white space made this algorithm work wrong:
var sentence = "dancing sentence";
var charSentence = sentence.ToCharArray();
var rs = "";
var flag = true;
for (var i = 0; i < charSentence.Length; i++)
{
if (charSentence[i] != ' ')
{
if (flag)
{
rs += charSentence[i].ToString().ToUpper();
}
else
{
rs += sentence[i].ToString().ToLower();
}
flag = !flag;
}
else
{
rs += " ";
}
}
Console.WriteLine(rs);

Try a simple Finite State Automata with just two states (upper == true/false); another suggestion is to use StringBuilder:
private static string ToDancing(string value) {
if (string.IsNullOrEmpty(value))
return value;
bool upper = false;
StringBuilder sb = new StringBuilder(value.Length);
foreach (var c in value)
if (char.IsLetter(c))
sb.Append((upper = !upper) ? char.ToUpper(c) : char.ToLower(c));
else
sb.Append(c);
return sb.ToString();
}
Test
var sentence = "dancing sentence";
Console.Write(ToDancing(sentence));
Outcome
DaNcInG sEnTeNcE

I think you should declare one more variable called isUpper. Now you have two variables, i indicates the index of the character that you are iterating next and isUpper indicates whether a letter should be uppercase.
You increment i as usual, but set isUpper to true at first:
// before the loop
boolean isUpper = true;
Then, rather than checking whether i is divisible by 2, check isUpper:
if (isUpper)
{
rs += charSentence[i].ToString().ToUpper();
}
else
{
rs += sentence[i].ToString().ToLower();
}
Immediately after the above if statement, "flip" isUpper:
isUpper = !isUpper;

Linq version
var sentence = "dancing sentence";
int i = 0;
string result = string.Concat(sentence.Select(x => { i += x == ' ' ? 0 : 1; return i % 2 != 0 ? char.ToUpper(x) : char.ToLower(x); }));
Sidenote:
please replace charSentence[i].ToString().ToUpper() with char.ToUpper(charSentence[i])

Thanks #Dmitry Bychenko. Best Approach. But i thought as per the OP's (might be a fresher...) mindset, what could be the solution. Here i have the code as another solution.
Lengthy code. I myself don't like but still representing
class Program
{
static void Main(string[] args)
{
var sentence = "dancing sentence large also";
string newString = string.Empty;
StringBuilder newStringdata = new StringBuilder();
string[] arr = sentence.Split(' ');
for (int i=0; i< arr.Length;i++)
{
if (i==0)
{
newString = ReturnEvenModifiedString(arr[i]);
newStringdata.Append(newString);
}
else
{
if(char.IsUpper(newString[newString.Length - 1]))
{
newString = ReturnOddModifiedString(arr[i]);
newStringdata.Append(" ");
newStringdata.Append(newString);
}
else
{
newString = ReturnEvenModifiedString(arr[i]);
newStringdata.Append(" ");
newStringdata.Append(newString);
}
}
}
Console.WriteLine(newStringdata.ToString());
Console.Read();
}
//For Even Test
private static string ReturnEvenModifiedString(string initialString)
{
string newString = string.Empty;
var temparr = initialString.ToCharArray();
for (var i = 0; i < temparr.Length; i++)
{
if (temparr[i] != ' ')
{
if (i % 2 == 0 && temparr[i] != ' ')
{
newString += temparr[i].ToString().ToUpper();
}
else
{
newString += temparr[i].ToString().ToLower();
}
}
}
return newString;
}
//For Odd Test
private static string ReturnOddModifiedString(string initialString)
{
string newString = string.Empty;
var temparr = initialString.ToCharArray();
for (var i = 0; i < temparr.Length; i++)
{
if (temparr[i] != ' ')
{
if (i % 2 != 0 && temparr[i] != ' ')
{
newString += temparr[i].ToString().ToUpper();
}
else
{
newString += temparr[i].ToString().ToLower();
}
}
}
return newString;
}
}
OUTPUT

Splitting CSV files with commas in the values [duplicate]

How to split the CSV file in c sharp? And how to display this?

I've been using the TextFieldParser Class in the Microsoft.VisualBasic.FileIO namespace for a C# project I'm working on. It will handle complications such as embedded commas or fields that are enclosed in quotes etc. It returns a string[] and, in addition to CSV files, can also be used for parsing just about any type of structured text file.

Display where? About splitting, the best way is to use a good library to that effect.
This library is pretty good, I can recommend it heartily.
The problems using naïve methods is that the usually fail, there are tons of considerations without even thinking about performance:
What if the text contains commas
Support for the many existing formats (separated by semicolon, or text surrounded by quotes, or single quotes, etc.)
and many others

Import Micorosoft.VisualBasic as a reference (I know, its not that bad) and use Microsoft.VisualBasic.FileIO.TextFieldParser - this handles CSV files very well, and can be used in any .Net language.

read the file one line at a time, then ...
foreach (String line in line.Split(new char[] { ',' }))
Console.WriteLine(line);

This is a CSV parser I use on occasion.
Usage: (dgvMyView is a datagrid type.)
CSVReader reader = new CSVReader("C:\MyFile.txt");
reader.DisplayResults(dgvMyView);
Class:
using System.IO;
using System.Text.RegularExpressions;
using System.Windows.Forms;
public class CSVReader
{
private const string ESCAPE_SPLIT_REGEX = "({1}[^{1}]*{1})*(?<Separator>{0})({1}[^{1}]*{1})*";
private string[] FieldNames;
private List<string[]> Records;
private int ReadIndex;
public CSVReader(string File)
{
Records = new List<string[]>();
string[] Record = null;
StreamReader Reader = new StreamReader(File);
int Index = 0;
bool BlankRecord = true;
FieldNames = GetEscapedSVs(Reader.ReadLine());
while (!Reader.EndOfStream)
{
Record = GetEscapedSVs(Reader.ReadLine());
BlankRecord = true;
for (Index = 0; Index <= Record.Length - 1; Index++)
{
if (!string.IsNullOrEmpty(Record[Index])) BlankRecord = false;
}
if (!BlankRecord) Records.Add(Record);
}
ReadIndex = -1;
Reader.Close();
}
private string[] GetEscapedSVs(string Data)
{
return GetEscapedSVs(Data, ",", "\"");
}
private string[] GetEscapedSVs(string Data, string Separator, string Escape)
{
string[] Result = null;
int Index = 0;
int PriorMatchIndex = 0;
MatchCollection Matches = Regex.Matches(Data, string.Format(ESCAPE_SPLIT_REGEX, Separator, Escape));
Result = new string[Matches.Count];
for (Index = 0; Index <= Result.Length - 2; Index++)
{
Result[Index] = Data.Substring(PriorMatchIndex, Matches[Index].Groups["Separator"].Index - PriorMatchIndex);
PriorMatchIndex = Matches[Index].Groups["Separator"].Index + Separator.Length;
}
Result[Result.Length - 1] = Data.Substring(PriorMatchIndex);
for (Index = 0; Index <= Result.Length - 1; Index++)
{
if (Regex.IsMatch(Result[Index], string.Format("^{0}[^{0}].*[^{0}]{0}$", Escape))) Result[Index] = Result[Index].Substring(1, Result[Index].Length - 2);
Result[Index] = Result[Index].Replace(Escape + Escape, Escape);
if (Result[Index] == null) Result[Index] = "";
}
return Result;
}
public int FieldCount
{
get { return FieldNames.Length; }
}
public string GetString(int Index)
{
return Records[ReadIndex][Index];
}
public string GetName(int Index)
{
return FieldNames[Index];
}
public bool Read()
{
ReadIndex = ReadIndex + 1;
return ReadIndex < Records.Count;
}
public void DisplayResults(DataGridView DataView)
{
DataGridViewColumn col = default(DataGridViewColumn);
DataGridViewRow row = default(DataGridViewRow);
DataGridViewCell cell = default(DataGridViewCell);
DataGridViewColumnHeaderCell header = default(DataGridViewColumnHeaderCell);
int Index = 0;
ReadIndex = -1;
DataView.Rows.Clear();
DataView.Columns.Clear();
for (Index = 0; Index <= FieldCount - 1; Index++)
{
col = new DataGridViewColumn();
col.CellTemplate = new DataGridViewTextBoxCell();
header = new DataGridViewColumnHeaderCell();
header.Value = GetName(Index);
col.HeaderCell = header;
DataView.Columns.Add(col);
}
while (Read())
{
row = new DataGridViewRow();
for (Index = 0; Index <= FieldCount - 1; Index++)
{
cell = new DataGridViewTextBoxCell();
cell.Value = GetString(Index).ToString();
row.Cells.Add(cell);
}
DataView.Rows.Add(row);
}
}
}

I had got the result for my query. its like simple like i had read a file using io.file. and all the text are stored into a string. After that i splitted with a seperator. The code is shown below.
using System;
using System.Collections.Generic;
using System.Text;
namespace CSV
{
class Program
{
static void Main(string[] args)
{
string csv = "user1, user2, user3,user4,user5";
string[] split = csv.Split(new char[] {',',' '});
foreach(string s in split)
{
if (s.Trim() != "")
Console.WriteLine(s);
}
Console.ReadLine();
}
}
}

The following function takes a line from a CSV file and splits it into a List<string>.
Arguments:
string line = the line to split
string textQualifier = what (if any) text qualifier (i.e. "" or "\"" or "'")
char delim = the field delimiter (i.e. ',' or ';' or '|' or '\t')
int colCount = the expected number of fields (0 means don't check)
Example usage:
List<string> fields = SplitLine(line, "\"", ',', 5);
// or
List<string> fields = SplitLine(line, "'", '|', 10);
// or
List<string> fields = SplitLine(line, "", '\t', 0);
Function:
private List<string> SplitLine(string line, string textQualifier, char delim, int colCount)
{
List<string> fields = new List<string>();
string origLine = line;
char textQual = '"';
bool hasTextQual = false;
if (!String.IsNullOrEmpty(textQualifier))
{
hasTextQual = true;
textQual = textQualifier[0];
}
if (hasTextQual)
{
while (!String.IsNullOrEmpty(line))
{
if (line[0] == textQual) // field is text qualified so look for next unqualified delimiter
{
int fieldLen = 1;
while (true)
{
if (line.Length == 2) // must be final field (zero length)
{
fieldLen = 2;
break;
}
else if (fieldLen + 1 >= line.Length) // must be final field
{
fieldLen += 1;
break;
}
else if (line[fieldLen] == textQual && line[fieldLen + 1] == textQual) // escaped text qualifier
{
fieldLen += 2;
}
else if (line[fieldLen] == textQual && line[fieldLen + 1] == delim) // must be end of field
{
fieldLen += 1;
break;
}
else // not a delimiter
{
fieldLen += 1;
}
}
string escapedQual = textQual.ToString() + textQual.ToString();
fields.Add(line.Substring(1, fieldLen - 2).Replace(escapedQual, textQual.ToString())); // replace escaped qualifiers
if (line.Length >= fieldLen + 1)
{
line = line.Substring(fieldLen + 1);
if (line == "") // blank final field
{
fields.Add("");
}
}
else
{
line = "";
}
}
else // field is not text qualified
{
int fieldLen = line.IndexOf(delim);
if (fieldLen != -1) // check next delimiter position
{
fields.Add(line.Substring(0, fieldLen));
line = line.Substring(fieldLen + 1);
if (line == "") // final field must be blank
{
fields.Add("");
}
}
else // must be last field
{
fields.Add(line);
line = "";
}
}
}
}
else // if there is no text qualifier, then use existing split function
{
fields.AddRange(line.Split(delim));
}
if (colCount > 0 && colCount != fields.Count) // count doesn't match expected so throw exception
{
throw new Exception("Field count was:" + fields.Count.ToString() + ", expected:" + colCount.ToString() + ". Line:" + origLine);
}
return fields;
}

Problem: Convert a comma separated string into an array where commas in "quoted strings,,," should not be considered as separators but as part of an entry
Input:
String: First,"Second","Even,With,Commas",,Normal,"Sentence,with ""different"" problems",3,4,5
Output:
String-Array: ['First','Second','Even,With,Commas','','Normal','Sentence,with "different" problems','3','4','5']
Code:
string sLine;
sLine = "First,\"Second\",\"Even,With,Commas\",,Normal,\"Sentence,with \"\"different\"\" problems\",3,4,5";
// 1. Split line by separator; do not split if separator is within quotes
string Separator = ",";
string Escape = '"'.ToString();
MatchCollection Matches = Regex.Matches(sLine,
string.Format("({1}[^{1}]*{1})*(?<Separator>{0})({1}[^{1}]*{1})*", Separator, Escape));
string[] asColumns = new string[Matches.Count + 1];
int PriorMatchIndex = 0;
for (int Index = 0; Index <= asColumns.Length - 2; Index++)
{
asColumns[Index] = sLine.Substring(PriorMatchIndex, Matches[Index].Groups["Separator"].Index - PriorMatchIndex);
PriorMatchIndex = Matches[Index].Groups["Separator"].Index + Separator.Length;
}
asColumns[asColumns.Length - 1] = sLine.Substring(PriorMatchIndex);
// 2. Remove quotes
for (int Index = 0; Index <= asColumns.Length - 1; Index++)
{
if (Regex.IsMatch(asColumns[Index], string.Format("^{0}[^{0}].*[^{0}]{0}$", Escape))) // If "Text" is sourrounded by quotes (but ignore double quotes => "Leave ""inside"" quotes")
{
asColumns[Index] = asColumns[Index].Substring(1, asColumns[Index].Length - 2); // "Text" => Text
}
asColumns[Index] = asColumns[Index].Replace(Escape + Escape, Escape); // Remove double quotes ('My ""special"" text' => 'My "special" text')
if (asColumns[Index] == null) asColumns[Index] = "";
}
The output array is asColumns

Converting multifasta parser from Python to C#

I am trying to convert a multi fasta parser from Python to C#. For the input
>header1
ACTG
GCTA
>header2
GATTACA
it would return the dictionary {'header2': 'GATTACA', 'header1': 'ACTGGCTA'}
The original Python code looks like:
def fastaParser(handle):
""" Adapted from https://github.com/biopython/biopython/blob/master/Bio/SeqIO/FastaIO.py#L39 """
fastaDict = {}
#Skip any text before the first record (e.g. blank lines, comments)
while True:
line = handle.readline()
if line == "":
return # Premature end of file, or just empty?
if line[0] == ">":
break
while True:
if line[0] != ">":
raise ValueError("Records in Fasta files should start with '>' character")
title = line[1:].rstrip()
lines = []
line = handle.readline()
while True:
if not line:
break
if line[0] == ">":
break
lines.append(line.rstrip())
line = handle.readline()
#Remove trailing whitespace, and any internal spaces
sequence = "".join(lines).replace(" ", "").replace("\r", "")
fastaDict[title] = sequence
if not line:
return fastaDict
if __name__ == '__main__':
with open('fasta.txt') as f:
print fastaParser(f)
What I have as C# code is (my code expects a string instead of an open filehandle):
public Dictionary<int, string> parseFasta(string multiFasta)
{
Dictionary<int, string> fastaDict = new Dictionary<int, string>();
using (System.IO.StringReader multiFastaReader = new System.IO.StringReader(multiFasta))
{
// Skip any text before the first record (e.g. blank lines, comments)
while (true)
{
string line = multiFastaReader.ReadLine();
if (line == "")
{
return fastaDict; // Premature end of file, or just empty?
}
if (line[0] == '>')
{
break;
}
}
while (true)
{
if (line[0] != '>') // <- Here I get the error: "the name 'line' does not exist in the current context
{
throw new Exception("Records in Fasta files should start with '>' character");
}
string title= line[1:].TrimEnd();
List<string> lines = new List<string>();
line = multiFastaReader.ReadLine();
while (true)
{
if (!line)
{
break;
}
if (line[0] == '>')
{
break;
}
lines.Add(line.TrimEnd());
line = multiFastaReader.ReadLine();
}
// Remove trailing whitespace, and any internal spaces
string sequence = String.Join("", lines).Replace(" ", "").Replace("\r", "");
fastaDict.Add(title, sequence);
if (!line)
{
return fastaDict;
}
}
}
}
The error that 'm getting is that Visual Studio says that the variables called line after the second while (true) don't exist in the current context.

I finally got it to work with this code:
public Dictionary<string, string> parseFasta(string multiFasta)
{
Dictionary<string, string> fastaDict = new Dictionary<string, string>();
using (System.IO.StringReader multiFastaReader = new System.IO.StringReader(multiFasta))
{
// Skip any text before the first record (e.g. blank lines, comments)
string line = multiFastaReader.ReadLine();
while (true)
{
if (line == "")
{
return fastaDict; // Premature end of file, or just empty?
}
if (line[0] == '>')
{
break;
}
}
while (true)
{
if (line[0] != '>')
{
throw new Exception("Records in Fasta files should start with '>' character");
}
string title= line.Substring(1, line.Length-1).TrimEnd();
List<string> lines = new List<string>();
line = multiFastaReader.ReadLine();
while (true)
{
if (line == "")
{
break;
}
if (line == null)
{
break;
}
if (line[0] == '>')
{
break;
}
lines.Add(line.TrimEnd());
line = multiFastaReader.ReadLine();
}
// Remove trailing whitespace, and any internal spaces
string sequence = String.Join("", lines).Replace(" ", "").Replace("\r", "");
fastaDict.Add(title, sequence);
if (line == null)
{
return fastaDict;
}
}
}
}

Checking for brackets and removing them

I have actually misunderstood the issue originally,
Basically I have checks to see if there is an error, and to check for certain horrible characters that will break it, however this will not work with brackets, i need to basically check if there are ANY brackets within the string before passing it through SQL and if there are, remove them outright from the string.
for example say I have a string that looks like
[I am a magical string with super powers!){
I wish to remove all of these horrible brackets!
if (compiler.Parser.GetErrors().Count == 0)
{
AstNode root = compiler.Parse(phrase.ToLower());
if (compiler.Parser.GetErrors().Count == 0)
{
try
{
fTextSearch = SearchGrammar.ConvertQuery(root, SearchGrammar.TermType.Inflectional);
}
catch
{
fTextSearch = phrase;
}
}
else
{
fTextSearch = phrase;
}
}
else
{
fTextSearch = phrase;
}
string[] errorChars = errorChars = new string[]
{
"'",
"&"
};
StringBuilder sb = new StringBuilder();
string[] splitString = fTextSearch.Split(errorChars, StringSplitOptions.None);
int numNewCharactersAdded = 0;
foreach (string itm in splitString)
{
sb.Append(itm); //append string
if (fTextSearch.Length > (sb.Length - numNewCharactersAdded))
{
sb.Append(fTextSearch[sb.Length - numNewCharactersAdded]); //append splitting character
sb.Append(fTextSearch[sb.Length - numNewCharactersAdded - 1]); //append it again
numNewCharactersAdded++;
}
}
string newString = sb.ToString();
//Union with the full text search
if (!string.IsNullOrEmpty(fTextSearch))
{
sql.AppendLine("UNION");
sql.AppendLine(commonClause);
sql.AppendLine(string.Format("AND CONTAINS(nt.text, '{0}', LANGUAGE 'English')", newString));
}

this is one way to do it. You can make it more sophisticated by having a set of characters passed in and then testing for those characters rather than hard coding for the brackets.
var someString = "[Hello"
if(someString.contains("["))
{
someString.Replace("[","");
}
if (someString.Contains("]"))
{
someString.Replace("]","");
}

If I understand you right, you just want to remove the brackets if they are not matching.
This will accomplish that:
public string MatchPair(string input, string item1, string item2)
{
var ix1 = input.IndexOf(item1);
var ix2 = input.IndexOf(item2);
if ((ix1 != -1) && (ix2 != -1))
{
return input;
}
if (ix1 == -1)
{
return this.CutString(input, ix2, item2);
}
if (ix2 == -1)
{
return this.CutString(input, ix1, item1);
}
return string.Empty;
}
public string CutString(string input, int ix, string item)
{
string left = input.Substring(0, ix);
string right = input.Substring(ix + item.Length);
return left + right;
}
Here is some testdata that I used:
var str1 = "[hello]";
var str2 = "[hello";
var str3 = "hel]lo";
var str4 = "hel[lo";
var res1 = this.MatchPair(str1, "[", "]");
var res2 = this.MatchPair(str2, "[", "]");
var res3 = this.MatchPair(str3, "[", "]");
var res4 = this.MatchPair(str4, "[", "]");

Create Space Between Capital Letters and Skip Space Between Consecutive

I get the way to create space "ThisCourse" to be "This Course"
Add Space Before Capital Letter By (EtienneT) LINQ Statement
But i cannot
Create Space Betweeen This "ThisCourseID" to be "This Course ID" without space between "ID"
And Is there a way to do this in Linq ??

Well, if it has to be a single linq statement...
var s = "ThisCourseIDMoreXYeahY";
s = string.Join(
string.Empty,
s.Select((x,i) => (
char.IsUpper(x) && i>0 &&
( char.IsLower(s[i-1]) || (i<s.Count()-1 && char.IsLower(s[i+1])) )
) ? " " + x : x.ToString()));
Console.WriteLine(s);
Output: "This Course ID More X Yeah Y"

var s = "ThisCourseID";
for (var i = 1; i < s.Length; i++)
{
if (char.IsLower(s[i - 1]) && char.IsUpper(s[i]))
{
s = s.Insert(i, " ");
}
}
Console.WriteLine(s); // "This Course ID"
You can improve this using StringBuilder if you are going to use this on very long strings, but for your purpose, as you presented it, it should work just fine.
FIX:
var s = "ThisCourseIDSomething";
for (var i = 1; i < s.Length - 1; i++)
{
if (char.IsLower(s[i - 1]) && char.IsUpper(s[i]) ||
s[i - 1] != ' ' && char.IsUpper(s[i]) && char.IsLower(s[i + 1]))
{
s = s.Insert(i, " ");
}
}
Console.WriteLine(s); // This Course ID Something

You don't need LINQ - but you could 'enumerate' and use lambda to make it more generic...
(though not sure if any of this makes sense)
static IEnumerable<string> Split(this string text, Func<char?, char?, char, int?> shouldSplit)
{
StringBuilder output = new StringBuilder();
char? before = null;
char? before2nd = null;
foreach (var c in text)
{
var where = shouldSplit(before2nd, before, c);
if (where != null)
{
var str = output.ToString();
switch(where)
{
case -1:
output.Remove(0, str.Length -1);
yield return str.Substring(0, str.Length - 1);
break;
case 0: default:
output.Clear();
yield return str;
break;
}
}
output.Append(c);
before2nd = before;
before = c;
}
yield return output.ToString();
}
...and call it like this e.g. ...
static IEnumerable<string> SplitLines(this string text)
{
return text.Split((before2nd, before, now) =>
{
if ((before2nd ?? 'A') == '\r' && (before ?? 'A') == '\n') return 0; // split on 'now'
return null; // don't split
});
}
static IEnumerable<string> SplitOnCase(this string text)
{
return text.Split((before2nd, before, now) =>
{
if (char.IsLower(before ?? 'A') && char.IsUpper(now)) return 0; // split on 'now'
if (char.IsUpper(before2nd ?? 'a') && char.IsUpper(before ?? 'a') && char.IsLower(now)) return -1; // split one char before
return null; // don't split
});
}
...and somewhere...
var text = "ToSplitOrNotToSplitTHEQuestionIsNow";
var words = text.SplitOnCase();
foreach (var word in words)
Console.WriteLine(word);
text = "To\r\nSplit\r\nOr\r\nNot\r\nTo\r\nSplit\r\nTHE\r\nQuestion\r\nIs\r\nNow";
words = text.SplitLines();
foreach (var word in words)
Console.WriteLine(word);
:)