I have a list like
List<string> TempList = new List<string> { "[66,X,X]", "[67,X,2]", "[x,x,x]" };
I need to add data to the dictionary from the above list
Dictionary<int, int> Dict = new Dictionary<int, int>();
so the Dict should contain
Key --> 66 value --> 67
i need to take 66(first value) from first string([66,X,X]) and 67(first value) from second string( [67,X,X]) and add it as a key value pair into the dictionary.
Now i'm following string replacing and looping methodology to do this .
Is there any way to do this in LINQ or Regular expression.
After your comment that you're starting from a list of lists, I understood what you were after. I'm reusing Jaroslav's 'GetNumber' function here. Wrote my sample with array of array of string, but should work just the same. The code below will throw if you have duplicate keys, which I presume is what you want if you're using a dictionary.
var input = new []
{
new [] { "[66,X,X]", "[67,X,2]", "[x,x,x]" },
new [] { "[5,X,X]", "[8,X,2]", "[x,x,x]" }
};
var query = from l in input
select new
{
Key = GetNumber(l.ElementAt(0)),
Value = GetNumber(l.ElementAt(1))
};
var dictionary = query.ToDictionary(x => x.Key, x => x.Value);
Here is an example using both string.Split() and a Regex:
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
List<string> data = new List<string>() { "[66,X,X]", "[67,X,2]", "[x,x,x]" };
addToDict(data);
Console.ReadKey();
}
private static void addToDict(List<string> items)
{
string key = items[0].Split('[', ',')[1];
string val = items[1].Split('[', ',')[1];
string pattern = #"(?:^\[)(\d+)";
Match m = Regex.Match(items[0], pattern);
key = m.Groups[1].Value;
m = Regex.Match(items[1], pattern);
val = m.Groups[1].Value;
_dict.Add(key, val);
}
static Dictionary<string, string> _dict = new Dictionary<string, string>();
}
}
i suspect that your example is quite contrived though, so there may be a better solution especially if you need to process large numbers of strings into key/value pairs (i deliberately hardcoded index values because your example was quite simple and i didn't want to over complicate the answer). If the input data is consistent in format then you can make assumptions like using fixed indexes, but if there is a possibility of some variance then there may need to be more code to check the validity of it.
You can use a regular expression to extract the value from each item in the list, and if you want, use LINQ to select out two lists and zip them together (in C# 4.0):
var regex = new Regex(#"\d+");
var allValues = TempList.Select(x =>int.Parse(regex.Match(x).Value));
var dictKeys = allValues.Where((x,index)=> index % 2 == 0); //even-numbered
var dictValues = allValues.Where((x,index)=> index % 2 > 0); //odd numbered
var dict = dictKeys.Zip(dictValues, (key,value) => new{key,value})
.ToDictionary(x=>x.key,x=>x.value);
If you're using C# 3.5, you can use Eric Lippert's implementation of Zip().
IF I understand correctly: you want to create linked nodes like 66 -> 67, 67 -> 68, ... n -> n+1?
I would not use LINQ:
private static int GetNumber(string s)
{
int endPos = s.IndexOf(',');
return Int32.Parse(s.Substring(1, endPos-1));
}
And in code:
int first, second;
for (int i = 1; i < TempList.Count; i++)
{
first = GetNumber(TempList[i - 1]);
second = GetNumber(TempList[i]);
Dict.Add(first, second);
}
You should also perform checking, etc.
The sample assumes a list with at least 2 items.
List<List<string>> source = GetSource();
Dictionary<int, int> result = source.ToDictionary(
tempList => GetNumber(tempList[0]),
tempList => GetNumber(tempList[1])
);
Related
I have a class that has a bunch of different variables and a couple lists 1 in particular holds ints(positionInts)
I also have a list(teamsList) for holding objects I have created from that class
now I would like to sort the team's list by positions values
Hopefully, I'm not being too vague as the project I'm working on is full of not well-written code so it can be hard to explain.
This function orders the list according to your precondition.
private List<String> OrderList(List<String> teams, int[] positions)
{
List<String> orderedTeams;
Dictionary<int, string> teamsToOrder = new Dictionary<int, string>();
int position = 0;
foreach (string team in teams)
{
teamsToOrder.Add(positions[position], teams[position]);
position = position + 1;
}
orderedTeams = teamsToOrder.OrderByDescending(team => team.Key).Select(team => team.Value).ToList();
return orderedTeams;
}
If I understand your question correctly, then you have list of arbitrary type, for example list of strings:
var teamsList = new List<String> { "team1", "team2", "team3", "team4" };
Next up, you have enumeration of integers:
var positionInts = new[] { 2, 3, 1, 0 };
And your goal is to order teamsList based on sequence numbers of the positionInts. In that case you can use following method:
static IEnumerable<T> OrderBySequence<T>(IEnumerable<T> source, IEnumerable<Int32> sequence)
{
for (var i = 0; i < Math.Min(source.Count(), sequence.Count()); i++)
{
var s = sequence.ElementAt(i);
if (s > -1 && s < source.Count())
{
yield return source.ElementAt(s);
}
}
}
Which will produce:
team3
team4
team2
team1
I need to read a file and put that data inside to different arrays.
My .txt file looks like:
w1;
1 2 3
w2;
3 4 5
w3;
4 5 6
I tried something like the following:
int[] w1 = new int [3];
int[] w2 = new int [3];
int[] w3 = new int [3];
string v = "w1:|w2:|w3:";
foreach (string line in File.ReadAllLines(#"D:\\Data.txt"))
{
string[] parts = Regex.Split(line, v);
I got that string but I have no idea how to cut every element of it to arrays showed above.
Rather than parsing the file and putting the arrays into three hardcoded variables corresponding to hardcoded names w1, w2 and w3, I would remove the hardcoding and parse the file into a Dictionary<string, int[]> like so:
public static class DataFileExtensions
{
public static Dictionary<string, int[]> ParseDataFile(string fileName)
{
var separators = new [] { ' ' };
var query = from pair in File.ReadLines(fileName).Chunk(2)
let key = pair[0].TrimEnd(';')
let value = (pair.Count < 2 ? "" : pair[1]).Split(separators, StringSplitOptions.RemoveEmptyEntries).Select(s => int.Parse(s, NumberFormatInfo.InvariantInfo)).ToArray()
select new { key, value };
return query.ToDictionary(p => p.key, p => p.value);
}
}
public static class EnumerableExtensions
{
// Adapted from the answer to "Split List into Sublists with LINQ" by casperOne
// https://stackoverflow.com/questions/419019/split-list-into-sublists-with-linq/
// https://stackoverflow.com/a/419058
// https://stackoverflow.com/users/50776/casperone
public static IEnumerable<List<T>> Chunk<T>(this IEnumerable<T> enumerable, int groupSize)
{
// The list to return.
List<T> list = new List<T>(groupSize);
// Cycle through all of the items.
foreach (T item in enumerable)
{
// Add the item.
list.Add(item);
// If the list has the number of elements, return that.
if (list.Count == groupSize)
{
// Return the list.
yield return list;
// Set the list to a new list.
list = new List<T>(groupSize);
}
}
// Return the remainder if there is any,
if (list.Count != 0)
{
// Return the list.
yield return list;
}
}
}
And you would use it as follows:
var dictionary = DataFileExtensions.ParseDataFile(fileName);
Console.WriteLine("Result of parsing {0}, encountered {1} data arrays:", fileName, dictionary.Count);
foreach (var pair in dictionary)
{
var name = pair.Key;
var data = pair.Value;
Console.WriteLine(" Data row name = {0}, values = [{1}]", name, string.Join(",", data));
}
Which outputs:
Result of parsing Question49341548.txt, encountered 3 data arrays:
Data row name = w1, values = [1,2,3]
Data row name = w2, values = [3,4,5]
Data row name = w3, values = [4,5,6]
Notes:
I parse the integer values using NumberFormatInfo.InvariantInfo to ensure consistency of parsing in all locales.
I break the lines of the file into chunks of two by using a lightly modified version of the method from this answer to Split List into Sublists with LINQ by casperOne.
After breaking the file into chunks of pairs of lines, I trim the ; from the first line in each pair and use that as the dictionary key. The second line in each pair gets parsed into an array of integer values.
If the names w1, w2 and so on are not unique, you could deserialize instead into a Lookup<string, int []> by replacing ToDictionary() with ToLookup().
Rather than loading the entire file into memory upfront using File.ReadAllLines(), I enumerate though it sequentially using File.ReadLines(). This should reduce memory usage without any additional complexity.
Sample working .Net fiddle.
Your RegEx doesn't actually do anything, you already have an array with each line separated. What you want to do is just ignore the lines that aren't data:
var lines = File.ReadAllLines(#"D:\\Data.txt");
for (int i = 1; i < lines.Length; i += 2) // i.e indexes 1, 3 and 5
{
string[] numbers = lines[i].Split(' ');
}
Or, you could just assign given that you know the order:
w1 = lines[1].Split(' ');
w2 = lines[3].Split(' ');
w3 = lines[5].Split(' ');
I have this code snippet as below which iterates over a split string.
if (!string.IsNullOrEmpty(profile.ContactNumber))
{
var splitContract = profile.ContactNumber.Split(new string[] { "and", "&" }, StringSplitOptions.RemoveEmptyEntries);
foreach (var contract in splitContract)
{
//check the split if it contains "x" or "X" character - if it does contain, it means it's a valid contract
if (contract.Contains("x") || contract.Contains("X"))
{
var condensedString = contract.Replace(" ", "");
var split = condensedString.Split(new char[] { 'x', 'X' });
GetNumbersOnly(split);
}
}
}
private void GetNumbersOnly(string[] inputArray)
{
var ListKeyValuePair = new List<KeyValuePair<string, string>>();
foreach (var item in inputArray)
{
var numberToAdd = Regex.Replace(item, "[^0-9]", "", RegexOptions.None);
ListKeyValuePair.Add(?, ?);
}
}
In GetNumbersOnly method, how can I populate List of KeyValuePair inside the for each loop?
The inputArray variable has an array element of [0] = 100, [1] = 5 for the first iteration and so on.
This is the desired output for the KeyValuePair {100, 5}, {200, 10}, {500, 15}.
Sorry, I can't seem to find any related scenario when I googled it. Any help with this is greatly appreciated.
Because the key and value are stored in separate array items, your logic is dependent on order. In cases like this, you should avoid for...each and instead use plain old for, which allows you to control the manner of iteration.
private void GetNumbersOnly(string[] inputArray)
{
var ListKeyValuePair = new List<KeyValuePair<string, string>>();
for (int i=0; i< inputArray.Length; i+=2) //The "2" here is very important!
{
var numberToAdd1 = Regex.Replace(inputArray[i], "[^0-9]", "", RegexOptions.None);
var numberToAdd2 = Regex.Replace(inputArray[i+1], "[^0-9]", "", RegexOptions.None);
ListKeyValuePair.Add(new KeyValuePair<string, string>(numberToAdd1, numberToAdd2));
}
}
The ListKeyValuePair.Add( ) function is expecting 1 field which is of type KeyValuePair. You need to make one of these with a new KeyValuePair() { key = item, value = numberToAdd };
Why are you keeping key value pairs in a list? Why not a Dictionary ? Do you want duplicate pairs?
I want to input a List<string[]> and
The output is a dictionary where the keys are unique strings used for an index and the values is an array of floats with each position in the array representing the count of the key for a string[] in the List<string[]>
So far here is what I attempted
static class CT
{
//Counts all terms in array
public static Dictionary<string, float[]> Termfreq(List<string[]> text)
{
List<string> unique = new List<string>();
foreach (string[] s in text)
{
List<string> groups = s.Distinct().ToList();
unique.AddRange(groups);
}
string[] index = unique.Distinct().ToArray();
Dictionary<string, float[]> countset = new Dictionary<string, float[]>();
return countset;
}
}
static void Main()
{
/* local variable definition */
List<string[]> doc = new List<string[]>();
string[] a = { "That", "is", "a", "cat" };
string[] b = { "That", "bat", "flew","over","the", "cat" };
doc.Add(a);
doc.Add(b);
// Console.WriteLine(doc);
Dictionary<string, float[]> ret = CT.Termfreq(doc);
foreach (KeyValuePair<string, float[]> kvp in ret)
{
Console.WriteLine("Key = {0}, Value = {1}", kvp.Key, kvp.Value);
}
Console.ReadLine();
}
I got stuck on the dictionary part. What is the most effective way to implement this?
It sounds like you could use something like:
var dictionary = doc
.SelectMany(array => array)
.Distinct()
.ToDictionary(word => word,
word => doc.Select(array => array.Count(x => x == word))
.ToArray());
In other words, first find the distinct set of words, then for each word, create a mapping.
To create a mapping, look at each array in the original document, and find the count of the occurrences of the word in that array. (So each array maps to an int.) Use LINQ to perform that mapping over the whole document, with ToArray creating an int[] for a particular word... and that's the value for that word's dictionary entry.
Note that this creates a Dictionary<string, int[]> rather than a Dictionary<string, float[]> - it seems more sensible to me, but you could always cast the result of Count to float if you really wanted to.
I have a Dictionary<string, int> and I am reading some strings from a list... I want to add them in the dictionary, but if the string is already in the dictionary, I want its value to increase by 1.
The code I tried is as below, but there are some strings that are increased with every input.. Is something wrong?
Dictionary<string, int> dictionary = new Dictionary<string, int>();
foreach (String recordline in tags)
{
String recordstag = recordline.Split('\t')[1];
String tagToDic = recordstag.Substring(0, (recordstag.Length-1) );
if (dictionary.ContainsKey(tagToDic) == false)
{
dictionary.Add(tagToDic, 1);
}
else
{
try
{
dictionary[tagToDic] = dictionary[tagToDic] + 1;
}
catch (KeyNotFoundException ex)
{
System.Console.WriteLine("X" + tagToDic + "X");
dictionary.Add(tagToDic, 1);
}
}
}
EDIT: To answer your comments... I am removing the last char of the string because it is always a blank space...
My input is like:
10000301 business 0 0,000
10000301 management & auxiliary services 0 0,000
10000316 demographie 0 0,000
10000316 histoire de france 0 0,000
10000347 economics 0 0,000
10000347 philosophy 1 0,500
and i want only the string like "business" or "management & auxiliary services" etc.
You are splitting each string in the input string array and selecting the 2nd string in the string array. Then you are removing the last character of this 2nd string using SubString. Hence all strings that differ only in the last character would be considered the same and incremented. Thats why you might be seeing "some strings that are increased with every input".
EDIT: If the purpose of removing the last char is to remove space, Use String.Trim instead.
Another edit is using TryGetValue instead of ContainsKey which performs better to increment your value. Code has been edited below.
Try this:
Dictionary<string, int> dictionary = new Dictionary<string, int>();
foreach(string recordline in tags)
{
string recordstag = recordline.Split('\t')[1].Trim();
int value;
if (!dictionary.TryGetValue(recordstag, out value))
dictionary.Add(recordstag, 1);
else
dictionary[recordstag] = value + 1;
}
No need for a dictionary, can be solved using this Linq query.
(Assuming you want the complete string after \t)
var q =
from s in tags.Select (t => t.Substring(t.IndexOf("\t")))
group s by s into g
select new
{
g.Key,
Count = g.Count()
};
And if you need it as a dictionary just add:
var dic = q.ToDictionary (x => x.Key, x => x.Count);
Your input string first split and then substring of it returned to tagToDic, So maybe n strings have a same tagToDic.
Extension method
public static void Increment(this Dictionary<string, int> dictionary, string key)
{
int val;
dictionary.TryGetValue(key, out val);
if (val != null)
dictionary[key] = val + 1;
}
Dictionary<string, int> dictionary = new Dictionary<string, int>();
// fill with some data
dictionary.Increment("someKey");
It's probably easier just to re-add the dictionary value after you retrieve the count from the existing one.
Here's some psuedo code to handle the look up logic.
Dictionary<string, int> _dictionary = new Dictionary<string, int>();
private void AdjustWordCount(string word)
{
int count;
bool success = _dictionary.TryGetValue(word, out count);
if (success)
{
//Remove it
_dictionary.Remove(word);
//Add it back in plus 1
_dictionary.Add(word, count + 1);
}
else //could not get, add it with a count of 1
{
_dictionary.Add(word, 1);
}
}
How about:
Dictionary<string, int> dictionary = new Dictionary<string, int>();
string delimitedTags = "some tab delimited string";
List<string> tags = delimitedTags.Split(new char[] {'\t'}, StringSplitOptions.None).ToList();
foreach (string tag in tags.Distinct())
{
dictionary.Add(tag, tags.Where(t => t == tag).Count());
}
If you have them in a list you could just group them and make your list.
list.GroupBy(recordline => recordline.Split('\t').Substring(0, (recordstag.Length-1),
(key, ienum) => new {word = key, count = ienum.Count()});
Then you can put that in a dictionary or iterate it or something.
Your dictionary code looks like it will function the way you expect.
My best guess is that your string-splitting code is not working correctly.
You'd have to give us some sample inputs to verify this though.
Anyway, your entire block of code could be simplified and rewritten with LINQ as:
var dictionary = tags
.Select(t => {
var recordstag = t.Split('\t')[1];
return recordstag.Substring(0, recordstag.Length-1);
})
.GroupBy(t => t)
.ToDictionary(k => k.Key, v => v.Count())
;