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Query list of dictionary C# Linq

I am trying to query a list of dictionary by dictionary key and value using linq. The following gives me the error of "cannot convert keyvaluepair to type bool."
Thanks in advance.
var list = new List<Dictionary<string, object>>();
foreach (DataRow row in wordCloud.Rows)
{
var dict = new Dictionary<string, object>();
foreach (DataColumn col in wordCloud.Columns)
{
dict[col.ColumnName] = row[col];
}
list.Add(dict);
}
if (!string.IsNullOrWhiteSpace(text))
{
var item = list.Where(dict => dict.Where(x => x.Key == "word" && x.Value == text)).FirstOrDefault();
}
Thanks this is what I am using.
var item = list.Where(dict => dict["WORD"].Equals(text)).FirstOrDefault();

Your compiler error is caused by your predicate in list.Where not using a Boolean expression. dict.Where(...) is going to produce an IEnumerable<KeyValuePair<K,V>>, which is not a Boolean operation. Furthermore, your technique misuses a dictionary, because it will only have one pair that has a given key, there is no need to loop over it. To deal with both issues, I suggest writing a method to investigate the dictionary and produce a Boolean result for matches.
bool DictionaryContainsText(Dictionary<string, object> dictionary, string text)
{
string key = "word";
if (dictionary.ContainsKey(key) && dictionary[key] != null)
{
return dictionary[key].Equals(text);
}
return false;
}
You can then consume this method in the filtering of your list.
var item = list.Where(dict => DictionaryContainsText(dict, text)).FirstOrDefault();
All that said, I wonder if you are starting from the wrong design? A DataTable to a List<Dictionary<K,V>> seems a bit less intuitive to use than a list of a defined type. Should you not consider defining a class with appropriately named (and typed!) properties that you could consume instead? This is left as an activity for you to consider.

Your error is happening because the predicate of list.Where( ... ) is dict => dict.Where( ... ) which isn't a Boolean value.
Depending on how you want your code to work, you could potentially replace it with list.FirstOrDefault(dict => dict.Any( ... )), which would eventually return the first dictionary that contains the key-value pair ("word", text). (I think this is the intended functionality of the code, but I can't be positive without further information.)

TextBox display closest match string

How can I get the string from a list that best match with a base string using the Levenshtein Distance.
This is my code:
{
string basestring = "Coke 600ml";
List<string> liststr = new List<string>
{
"ccoca cola",
"cola",
"coca cola 1L",
"coca cola 600",
"Coke 600ml",
"coca cola 600ml",
};
Dictionary<string, int> resultset = new Dictionary<string, int>();
foreach(string test in liststr)
{
resultset.Add(test, Ldis.Compute(basestring, test));
}
int minimun = resultset.Min(c => c.Value);
var closest = resultset.Where(c => c.Value == minimun);
Textbox1.Text = closest.ToString();
}
In this example if I run the code I get 0 changes in string number 5 from the list, so how can I display in the TextBox the string itself?
for exemple : "Coke 600ml" Right now my TextBox just returns:
System.Linq.Enumerable+WhereEnumerableIterator`1
[System.Collections.Generic.KeyValuePair`2[System.String,System.Int32]]
Thanks.

Try this
var closest = resultset.First(c => c.Value == minimun);
Your existing code is trying to display a list of items in the textbox. I looks like it should just grab a single item where Value == min

resultset.Where() returns a list, you should use
var closest = resultset.First(c => c.Value == minimun);
to select a single result.
Then the closest is a KeyValuePair<string, int>, so you should use
Textbox1.Text = closest.Key;
to get the string. (You added the string as Key and changes count as Value to resultset earilier)

There is a good solution in code project
http://www.codeproject.com/Articles/36869/Fuzzy-Search

It can be very much simplified like so:
var res = liststr.Select(x => new {Str = x, Dist = Ldis.Compute(basestring, x)})
.OrderBy(x => x.Dist)
.Select(x => x.Str)
.ToArray();
This will order the list of strings from most similar to least similar.
To only get the most similar one, simply replace ToArray() with First().
Short explanation:
For every string in the list, it creates an anonymous type which contains the original string and it's distance, computed using the Ldis class. Then, it orders the collection by the distance and maps back to the original string, so as to lose the "extra" information calculated for the ordering.

Parse style attribute collection using linq

I want to parse an SVG style attribute, which is just a delimited string, e.g.
"fill:#e2b126;stroke:#010101;stroke-width:0.3177;stroke-miterlimit:10"
into a Dictionary<string,string> so that I can perform some processing on it.
Here's what I have, which does the job, but I'd like to make it neater using a linq projection, just can't seem to get the syntax. I tried using .Select().ToDictionary etc, but no joy. Thanks:
string attributes = "fill:#e2b126;stroke:#010101;stroke-width:0.3177;stroke-miterlimit:10";
var pairs = attributes.Split(';').ToList();
var dic = new Dictionary<string, string>();
pairs.ForEach(p =>
{
var pair = p.Split(':');
dic.Add(pair[0], pair[1]);
});
foreach (var k in dic.Keys)
{
Console.WriteLine(k + " " + dic[k]);
}
Expected output:
fill #e2b126
stroke #010101
stroke-width 0.3177
stroke-miterlimit 10

Try the following
string attributes = "fill:#e2b126;stroke:#010101;stroke-width:0.3177;stroke-miterlimit:10";
var map = attributes
.Split(new []{';'}, StringSplitOptions.RemoveEmptyEntries)
.Select(x => x.Split(new []{':'}, StringSplitOptions.RemoveEmptyEntries))
.ToDictionary(p => p[0], p => p[1]);
Breakdown
The first Split call will return an array of String values where every entry is in the key:value format. The following Select call will convert every one of those entries into a string[] where the first element is the key and the second is the value. The ToDictionary call just expressly performs this mapping

Convert a delimted string to a dictionary<string,string> in C#

I have a string of the format
"key1=value1;key2=value2;key3=value3;"
I need to convert it to a dictionary for the above mentioned key value pairs.
What would be the best way to go about this?
Thanks.

Something like this?
var dict = text.Split(new[] {';'}, StringSplitOptions.RemoveEmptyEntries)
.Select(part => part.Split('='))
.ToDictionary(split => split[0], split => split[1]);
Of course, this will fail if the assumptions aren't met. For example, an IndexOutOfRangeException could be thrown if the text isn't in the right format and an ArgumentException will be thrown if there are duplicate keys. Each of these scenarios will require different modifications. If redundant white-space could be present, you may need some string.Trim calls as necessary.

Updated Ani's to take in account the semi colon at the end. The where clause will ensure that you have a key and value before creating and entry.
var dictionary = "key1=value1;key2=value2;key3=value3;"
.Split(';')
.Select (part => part.Split('='))
.Where (part => part.Length == 2)
.ToDictionary (sp => sp[0], sp => sp[1]);

You could do this using JSON string, for example:
var dic = JsonConvert.DeserializeObject<Dictionary<int, string>>("{'1':'One','2':'Two','3':'Three'}");

Behold the awesome whitespace ignoring, correcting for last value having or not having a semicolon power of regular expressions:
var dict = Regex.Matches("key1 = value1; key2 = value2 ; key3 = value3", #"\s*(.*?)\s*=\s*(.*?)\s*(;|$)")
.OfType<Match>()
.ToDictionary(m => m.Groups[1].Value, m => m.Groups[2].Value);
But seriously though, Ani deserves props for the .ToDictionary(). I would never have thought of that.

You could write it like this or loop over it to do it yourself. Either way. Ultimately, you're splitting on ; to get the item pairs, then on = to get the key and value.
string input = "key1=value1;key2=value2;key3=value3;";
Dictionary<string, string> dictionary =
input.TrimEnd(';').Split(';').ToDictionary(item => item.Split('=')[0], item => item.Split('=')[1]);
Loop version:
Dictionary<string, string> dictionary = new Dictionary<string, string>();
string[] items = input.TrimEnd(';').Split(';');
foreach (string item in items)
{
string[] keyValue = item.Split('=');
dictionary.Add(keyValue[0], keyValue[1]);
}

Most elegant way to convert string array into a dictionary of strings

Is there a built-in function for converting a string array into a dictionary of strings or do you need to do a loop here?

Assuming you're using .NET 3.5, you can turn any sequence (i.e. IEnumerable<T>) into a dictionary:
var dictionary = sequence.ToDictionary(item => item.Key,
item => item.Value)
where Key and Value are the appropriate properties you want to act as the key and value. You can specify just one projection which is used for the key, if the item itself is the value you want.
So for example, if you wanted to map the upper case version of each string to the original, you could use:
var dictionary = strings.ToDictionary(x => x.ToUpper());
In your case, what do you want the keys and values to be?
If you actually just want a set (which you can check to see if it contains a particular string, for example), you can use:
var words = new HashSet<string>(listOfStrings);

You can use LINQ to do this, but the question that Andrew asks should be answered first (what are your keys and values):
using System.Linq;
string[] myArray = new[] { "A", "B", "C" };
myArray.ToDictionary(key => key, value => value);
The result is a dictionary like this:
A -> A
B -> B
C -> C

IMO, When we say an Array we are talking about a list of values that we can get a value with calling its index (value => array[index]), So a correct dictionary is a dictionary with a key of index.
And with thanks to #John Skeet, the proper way to achieve that is:
var dictionary = array
.Select((v, i) => new {Key = i, Value = v})
.ToDictionary(o => o.Key, o => o.Value);
Another way is to use an extension method like this:
public static Dictionary<int, T> ToDictionary<T>(this IEnumerable<T> array)
{
return array
.Select((v, i) => new {Key = i, Value = v})
.ToDictionary(o => o.Key, o => o.Value);
}

If you need a dictionary without values, you might need a HashSet:
var hashset = new HashSet<string>(stringsArray);

What do you mean?
A dictionary is a hash, where keys map to values.
What are your keys and what are your values?
foreach(var entry in myStringArray)
myDictionary.Add(????, entry);

I'll assume that the question has to do with arrays where the keys and values alternate. I ran into this problem when trying to convert redis protocol to a dictionary.
private Dictionary<T, T> ListToDictionary<T>(IEnumerable<T> a)
{
var keys = a.Where((s, i) => i % 2 == 0);
var values = a.Where((s, i) => i % 2 == 1);
return keys
.Zip(values, (k, v) => new KeyValuePair<T, T>(k, v))
.ToDictionary(kv => kv.Key, kv => kv.Value);
}

Dictionary<int, string> dictionaryTest = new Dictionary<int, string>();
for (int i = 0; i < testArray.Length; i++)
{
dictionaryTest.Add(i, testArray[i]);
}
foreach (KeyValuePair<int, string> item in dictionaryTest)
{
Console.WriteLine("Array Position {0} and Position Value {1}",item.Key,item.Value.ToString());
}

The Question is not very clear, but Yes you can convert a string to Dictionary provided the string is delimited with some characters to support Dictionary<Key,Value> pair
So if a string is like a=first;b=second;c=third;d=fourth you can split it first based on ; then on = to create a Dictionary<string,string> the below extension method does the same
public static Dictionary<string, string> ToDictionary(this string stringData, char propertyDelimiter = ';', char keyValueDelimiter = '=')
{
Dictionary<string, string> keyValuePairs = new Dictionary<string, string>();
Array.ForEach<string>(stringData.Split(propertyDelimiter), s =>
{
if(s != null && s.Length != 0)
keyValuePairs.Add(s.Split(keyValueDelimiter)[0], s.Split(keyValueDelimiter)[1]);
});
return keyValuePairs;
}
and can use it like
var myDictionary = "a=first;b=second;c=third;d=fourth".ToDictionary();
since the default parameter is ; & = for the extension method.

You can create a dictionary from an IEnumerable<T>, including an array, via:
var dictionary = myEnumerable.ToDictionary(element => element.Key,
element => element.Value)
where Key and Value are the key and value you want to store in each dictionary element. Available in .NET Framework 3.5+/.NET Core 1.0+/.NET 5.0+. Official documentation.
If you want the dictionary values to be the elements from the original enumerable:
var dictionary = myEnumerable.ToDictionary(element => element.Key)
If you only need high-performance set operations, you may be able to use:
var words = new HashSet<string>(listOfStrings);
In simple terms, the HashSet class can be thought of as a Dictionary<TKey,TValue> collection without values. Official documentation.
(Note that a 'sequence' in an entirely unrelated object.
Originally submitted an existing answer edit but it was rejected by the author so posting separately, including with links to the official Microsoft documentation.)