I have an input file that includes data on an entertainer and their performance score. For example,
1. Bill Monohan from North Town 10.54
2. Mary Greenberg from Ohio 3.87
3. Sean Hollen from Markell 7.22
I want to be able to take the last number from a line (their score), perform some math on it, and then replace the old score with the new score.
Here's a brief piece of code for what I'm trying to do:
string line;
StreamReader reader = new StreamReader(#"file.txt");
//Read each line and split by spaces into a List.
while ((line = reader.ReadLine())!= null){
//Find last item in List and convert to a Double in order to perform calculations.
List<string> l = new List<string>();
l = line.Split(null).ToList();
string lastItem = line.Split(null).Last();
Double newItem = Convert.ToDouble(lastItem);
/*Do some math*/
/*Replace lastItem with newItem*/
System.Console.WriteLine(line); }
When I write the new line, nothing changes but I want lastItem to be switched with newItem at the end of the line now. I've tried using:
l[l.Length - 1] = newItem.ToString();
But I'm getting no luck. I just need the best way to replace the last value of a string List like this. I've been going at this for a few hours now and I'm almost at the end of my rope.
Please help me c# masters!
You can use regular expression MatchEvaluator to get number from each line, do calculations, and replace original number with new one:
string line = "1. Bill Monohan from North Town 10.54";
line = Regex.Replace(line, #"(\d+\.?\d*)$", m => {
decimal value = Decimal.Parse(m.Groups[1].Value);
value = value * 2; // calculation
return value.ToString();
});
This regex captures decimal number at the end of input string. Output:
1. Bill Monohan from North Town 21.08
You're not changing anything to your line object before doing your WriteLine.
You will have to rebuild your line, something like this:
var items = string.Split();
items.Last() = "10";//Replace
var line = string.Join(" ", items)
Tip: strings are immutable, look it up.
This should work:
//var l = new List<string>(); // you don't need this
var l = line.Split(null).ToList();
var lastItem = l.Last(); // line.Split(null).Last(); don't split twice
var newItem = Convert.ToDouble(lastItem, CultureInfo.InvariantCulture);
/*Do some math*/
/*Replace lastItem with newItem*/
l[l.Count - 1] = newItem.ToString(); // change the last element
//Console.WriteLine(line); // line is the original string don't work
Console.WriteLine(string.Join(" ", l)); // create new string
This would probably do the job for you. A word on reading files though, if possible, ie they fit in memory, read the entire file at once, it gives you one disk access (well, depends on file size, but yeah) and you do not have to worry about filehandles.
// Read the stuff from the file, gets an string[]
var lines = File.ReadAllLines(#"file.txt");
foreach (var line in lines)
{
var splitLine = line.Split(' ');
var score = double.Parse(splitLine.Last(), CultureInfo.InvariantCulture);
// The math wizard is in town!
score = score + 3;
// Put it back
splitLine[splitLine.Count() - 1] = score.ToString();
// newLine is the new line, what should we do with it?
var newLine = string.Join(" ", splitLine);
// Lets print it cause we are out of ideas!
Console.WriteLine(newLine);
}
What do you want to do with the end result? Do you want it written back to file?
Try this
string subjectString = "Sean Hollen from Markell 7.22";
double Substring =double.Parse(subjectString.Substring(subjectString.IndexOf(Regex.Match(subjectString, #"\d+").Value), subjectString.Length - subjectString.IndexOf(Regex.Match(subjectString, #"\d+").Value)).ToString());
double NewVal = Substring * 10; // Or any of your operation
subjectString = subjectString.Replace(Substring.ToString(), NewVal.ToString());
Note: This will not work if the number appears twice on the same line
You are creating and initializing the list in a loop, hence it contains always only the current line. Do you want to find the highest score of all entertainers or the highest score of each entertainer (in case an entertainer could repeat in the file)?
However, here is an approach that gives you both:
var allWithScore = File.ReadAllLines(path)
.Select(l =>
{
var split = l.Split();
string entertainer = string.Join(" ", split.Skip(1).Take(split.Length - 2));
double score;
bool hasScore = double.TryParse(split.Last(), NumberStyles.Float, CultureInfo.InvariantCulture, out score);
return new { line = l, split, entertainer, hasScore, score };
})
.Where(x => x.hasScore);
// highest score of all:
double highestScore = allWithScore.Max(x => x.score);
// entertainer with highest score
var entertainerWithHighestScore = allWithScore
.OrderByDescending(x => x.score)
.GroupBy(x => x.entertainer)
.First();
foreach (var x in entertainerWithHighestScore)
Console.WriteLine("Entertainer:{0} Score:{1}", x.entertainer, x.score);
// all entertainer's highest scores:
var allEntertainersHighestScore = allWithScore
.GroupBy(x => x.entertainer)
.Select(g => g.OrderByDescending(x => x.score).First());
foreach (var x in allEntertainersHighestScore)
Console.WriteLine("Entertainer:{0} Score:{1}", x.entertainer, x.score);
Related
I want to display strings in a file that begins with the letter "F" (var target = "F";) and then print it in footlockerExistingBlogTextBox however only display 5 strings/lines. The file that holds the array contains more that 5 strings that begin with "F" and so I only want to display the last 5 latest entries. Thanks for your help in advance. Much appreciated.
Below displays my code:
var target = "F";
var results = footlockerArray.Where(r => r.StartsWith(target)).Reverse();
foreach (string result in results)
{
footlockerExistingBlogTextBox.Text += result;
}
for (int i = footlockerArray.Length - 1; i > footlockerArray.Length - 5; i--)
{
footlockerArray.Reverse();
footlockerExistingBlogTextBox.Text += footlockerArray[i];
}
Use Enumerable.Take and you can get the results like:
var results = footlockerArray.Where(r => r.StartsWith(target))
.OrderByDescending(r=> r)
.Take(5);
Then to get a string separated by a new line you can use string.Join like:
footlockerExistingBlogTextBox.Text = string.Join(Environment.NewLine, results);
Reverse and use Take(5):
footlockerArray
.Where(o => o.StartsWith("F"))
.Reverse()
.Take(5)
.Reverse()
.ToList()
.ForEach(o => footlockerExistingBlogTextBox.Text += o);
I have a list of strings that look like this:
List<string> list = new List<string>;
list.add("AAPL7131221P00590000");
list.add("AAPL7131206C00595000");
list.add("AAPL7131213P00600000");
I would like to remove the date that is between AAPL7 and the next letter which is either C or P, and then add it to a new list. How do I use regex to get: 131221, 131206, or 131212 so I can populate a new list?
You don't need regex for this one, you can just use Substring, assuming that all your inputs will be the same number of characters.
var startingString = "AAPL7"; // holds whatever the starting string is
var input = "AAPL7131221P00590000";
var outputDate = input.Substring(startingString.Length, 6);
So if you wanted to make this a one-liner for making a collection:
List<string> allDates = yourInputValues
.Select(x => x.Substring(startingString.Length, 6))
.ToList();
Consider the following code snippet...
string startPattern = "AAPL7"; // GOOGL, GOOG, etc
List<string> newlist = list
.Select(n => Regex.Match(n, string.Format(#"(?<=^{0})\d+", startPattern)).Value)
.ToList();
//Regex regex = new Regex("(\\w{5})(\\d*)(\\w*)");
Regex regex = new Regex("(\\w*)(\\d{6})([PC])(\\d*)");
List<string> list = new List<string>();
list.Add("AAPL7131221P00590000");
list.Add("AAPL7131206C00595000");
list.Add("AAPL7131213P00600000");
List<string> extracted = new List<string>();
foreach (string item in list)
{
extracted.Add(regex.Split(item)[2]);
}
Is this what you want?
I just add something that may help in case you have the different date length (i.e. 14131 for 31st, January 2014)
string startpart = "AAPL7"; // or whatever
string mainstring = "AAPL714231P00590000"; // or any other input
mainstring = mainstring.Substring(startpart.Length); //this will through away startpart
int index;
if (mainstring.IndexOf("P") >= 0) index = mainstring.IndexOf("P"); //if there is no "P" it gives -1
else index = mainstring.IndexOf("C");
string date = mainstring.Substring(0,index);
i guess it is a safe approach to handle wider cases
I get many lines of String as an Input that look like this. The Input is a String that comes from
theObjects.Runstate;
each #VAR;****;#ENDVAR; represents one Line and one step in the loop.
#VAR;Variable=Speed;Value=Fast;Op==;#ENDVAR;#VAR;Variable=Fabricator;Value=Freescale;Op==;#ENDVAR;
I split it, to remove the unwanted fields, like #VAR,#ENDVAR and Op==.
The optimal Output would be:
Speed = Fast;
Fabricator = Freescale; and so on.
I am able to cut out the #VAR and the#ENDVAR. Cutting out the "Op==" wont be that hard, so thats now not the main focus of the question. My biggest concern right now is,thatI want to print the Output as a Text-File. To print an Array I would have to loop over it. But in every iteration, when I get a new line, I overwrite the Array with the current splitted string. I think the last line of the Inputfile is an empty String, so the Output I get is just an empty Text-File. It would be nice if someone could help me.
string[] w;
Textwriter tw2;
foreach (EA.Element theObjects in myPackageObject.Elements)
{
theObjects.Type = "Object";
foreach (EA.Element theElements in PackageHW.Elements)
{
if (theObjects.ClassfierID == theElements.ElementID)
{
t = theObjects.RunState;
w = t.Replace("#ENDVAR;", "#VAR;").Replace("#VAR;", ";").Split(new string[] { ";" }, StringSplitOptions.RemoveEmptyEntries);
foreach (string s in w)
{
tw2.WriteLine(s);
}
}
}
}
This linq-query gives the exptected result:
var keyValuePairLines = File.ReadLines(pathInputFile)
.Select(l =>
{
l = l.Replace("#VAR;", "").Replace("#ENDVAR;", "").Replace("Op==;", "");
IEnumerable<string[]> tokens = l.Split(new[]{';'}, StringSplitOptions.RemoveEmptyEntries)
.Select(t => t.Split('='));
return tokens.Select(t => {
return new KeyValuePair<string, string>(t.First(), t.Last());
});
});
foreach(var keyValLine in keyValuePairLines)
foreach(var keyVal in keyValLine)
Console.WriteLine("Key:{0} Value:{1}", keyVal.Key, keyVal.Value);
Output:
Key:Variable Value:Speed
Key:Value Value:Fast
Key:Variable Value:Fabricator
Key:Value Value:Freescale
If you want to output it to another text-file with one key-value pair on each line:
File.WriteAllLines(pathOutputFile, keyValuePairLines.SelectMany(l =>
l.Select(kv => string.Format("{0}:{1}", kv.Key, kv.Value))));
Edit according to your question in the comment:
"What would I have to change/add so that the Output is like this. I
need AttributeValuePairs, for example: Speed = Fast; or Fabricator =
Freescale ?"
Now i understand the logic, you have key-value pairs but you are interested only in the values. So every two key-values belong together, the first value of a pair specifies the attibute and the second value the value of that attribute(f.e. Speed=Fast).
Then it's a little bit more complicated:
var keyValuePairLines = File.ReadLines(pathInputFile)
.Select(l =>
{
l = l.Replace("#VAR;", "").Replace("#ENDVAR;", "").Replace("Op==;", "");
string[] tokens = l.Split(new[]{';'}, StringSplitOptions.RemoveEmptyEntries);
var lineValues = new List<KeyValuePair<string, string>>();
for(int i = 0; i < tokens.Length; i += 2)
{
// Value to a variable can be found on the next index, therefore i += 2
string[] pair = tokens[i].Split('=');
string key = pair.Last();
string value = null;
string nextToken = tokens.ElementAtOrDefault(i + 1);
if (nextToken != null)
{
pair = nextToken.Split('=');
value = pair.Last();
}
var keyVal = new KeyValuePair<string, string>(key, value);
lineValues.Add(keyVal);
}
return lineValues;
});
File.WriteAllLines(pathOutputFile, keyValuePairLines.SelectMany(l =>
l.Select(kv=>string.Format("{0} = {1}", kv.Key, kv.Value))));
Output in the file with your single sample-line:
Speed = Fast
Fabricator = Freescale
In C# what would be the best way of splitting this sort of string?
%%x%%a,b,c,d
So that I end up with the value between the %% AND another variable containing everything right of the second %%
i.e. var x = "x"; var y = "a,b,c,d"
Where a,b,c.. could be an infinite comma seperated list. I need to extract the list and the value between the two double-percentage signs.
(To combat the infinite part, I thought perhaps seperating the string out to: %%x%% and a,b,c,d. At this point I can just use something like this to get X.
var tag = "%%";
var startTag = tag;
int startIndex = s.IndexOf(startTag) + startTag.Length;
int endIndex = s.IndexOf(tag, startIndex);
return s.Substring(startIndex, endIndex - startIndex);
Would the best approach be to use regex or use lots of indexOf and substring to do the extracting based on te static %% characters?
Given that what you want is "x,a,b,c,d" the Split() function is actually pretty powerful and regex would be overkill for this.
Here's an example:
string test = "%%x%%a,b,c,d";
string[] result = test.Split(new char[] { '%', ',' }, StringSplitOptions.RemoveEmptyEntries);
foreach (string s in result) {
Console.WriteLine(s);
}
Basicly we ask it to split by both '%' and ',' and ignore empty results (eg. the result between "%%"). Here's the result:
x
a
b
c
d
To Extract X:
If %% is always at the start then;
string s = "%%x%%a,b,c,d,h";
s = s.Substring(2,s.LastIndexOf("%%")-2);
//Console.WriteLine(s);
Else;
string s = "v,u,m,n,%%x%%a,b,c,d,h";
s = s.Substring(s.IndexOf("%%")+2,s.LastIndexOf("%%")-s.IndexOf("%%")-2);
//Console.WriteLine(s);
If you need to get them all at once then use this;
string s = "m,n,%%x%%a,b,c,d";
var myList = s.ToArray()
.Where(c=> (c != '%' && c!=','))
.Select(c=>c).ToList();
This'll let you do it all in one go:
string pattern = "^%%(.+?)%%(?:(.+?)(?:,|$))*$";
string input = "%%x%%a,b,c,d";
Match match = Regex.Match(input, pattern);
if (match.Success)
{
// "x"
string first = match.Groups[1].Value;
// { "a", "b", "c", "d" }
string[] repeated = match.Groups[2].Captures.Cast<Capture>()
.Select(c => c.Value).ToArray();
}
You can use the char.IsLetter to get all the list of letter
string test = "%%x%%a,b,c,d";
var l = test.Where(c => char.IsLetter(c)).ToArray();
var output = string.Join(", ", l.OrderBy(c => c));
Since you want the value between the %% and everything after in separate variables and you don't need to parse the CSV, I think a RegEx solution would be your best choice.
var inputString = #"%%x%%a,b,c,d";
var regExPattern = #"^%%(?<x>.+)%%(?<csv>.+)$";
var match = Regex.Match(inputString, regExPattern);
foreach (var item in match.Groups)
{
Console.WriteLine(item);
}
The pattern has 2 named groups called x and csv, so rather than just looping, you can easily reference them by name and assign them to values:
var x = match.Groups["x"];
var y = match.Groups["csv"];
Text File:
$3.00,0.00,0.00,1.00,L55894M8,$3.00,0.00,0.00,2.00,L55894M9
How do I split the line and get the serial number like L55894M8 and L55894M9?
To get the data that appears after the 4th comma and 9th comma, you would want to do:
var pieces = line.Split(',');
var serial1 = line[3];
var serial2 = line[8];
Edit: Upon further reflection, it appears your file has records that begin with $ and end with the next record. If you want these records, along with the serial number (which appears to be the last field) you can do:
var records = line.TrimStart('$').Split('$');
var recordObjects = records.Select(r => new { Line = r, Serial = r.TrimEnd(',').Split(',').Last() });
In your sample you means want to get the words in index of ( 4 , 9 , 14 .... )
And the five words as a party .
So you can try this way.....
static void Main(string[] args)
{
string strSample = "$3.00,0.00,0.00,1.00,L55894M8,$3.00,0.00,0.00,2.00,L55894M9";
var result = from p in strSample.Split(',').Select((v, i) => new { Index = i, Value = v })
where p.Index % 5 == 4
select p.Value;
foreach (var r in result)
{
Console.WriteLine(r);
}
Console.ReadKey();
}
if the file is in a string you can use the string's .split(',') method then check each element of the resulting array. Or grab every 5th element if that pattern of data is seen throughout.
var str = "$3.00,0.00,0.00,1.00,L55894M8,$3.00,0.00,0.00,2.00,L55894M9";
var fieldArray = str.Split(new[] { ',' });
var serial1 = fieldArray[4]; // "L55894M8"
var serial2 = fieldArray[9]; // "L55894M9"
Try regular expression.
string str = "$3.00,0.00,0.00,1.00,L55894M8,$3.00,0.00,0.00,2.00,L55894M9";
string pat = #"L[\w]+";
MatchCollection ar= Regex.Matches(str, pat);
foreach (var t in ar)
Console.WriteLine(t);