[英]C# Distinct in LINQ query
更改一些代碼后,我遇到了問題。 我的想法是這樣的:我正在計算文檔中的單詞數,但是每個文檔僅包含一個單詞的一個副本,例如:
文檔1 = Smith Smith Smith Smith Smith => Smith x1
文檔2 = Smith Alan Alan => Smith x1,Alan x1
文檔3 = John John => John x1
但鐵匠的總人數應:
史密斯(Smith)x2(在3個文檔中有2個),艾倫(Alan)x1(3個文檔中有1個),約翰(x1)(3個文檔中有1個)
我認為在我有一個單獨的distinct方法之前(它計算所有單詞,如果distinct = false
),現在它只產生1
。
之前的代碼:
private Dictionary<string, int> tempDict = new Dictionary<string, int>();
private void Splitter(string[] file)
{
tempDict = file
.SelectMany(i => File.ReadAllLines(i)
.SelectMany(line => line.Split(new[] { ' ' }, StringSplitOptions.RemoveEmptyEntries))
.AsParallel()
.Select(word => word.ToLower())
.Distinct())
.GroupBy(word => word)
.ToDictionary(g => g.Key, g => g.Count());
}
應該對其進行更改,以便它返回字典,但是在制作應用的過程中,將其更改為以下代碼:
private Dictionary<string, int> Splitter(string[] file, bool distinct, bool pairs)
{
var query = file
.SelectMany(i => File.ReadLines(i)
.SelectMany(line => line.Split(new[] { ' '}, StringSplitOptions.RemoveEmptyEntries))
.AsParallel()
.Select(word => word.ToLower())
.Where(word => !word.All(char.IsDigit)));
if (distinct)
{
query = query.Distinct();
}
if (pairs)
{
var pairWise = query.Pairwise((first, second) => string.Format("{0} {1}", first, second));
return query
.Concat(pairWise)
.GroupBy(word => word)
.ToDictionary(g => g.Key, g => g.Count());
}
return query
.GroupBy(word => word)
.ToDictionary(g => g.Key, g => g.Count());
}
還要注意query = file.Distinct();
僅返回文檔名稱。 因此,必須有所不同。
@edit這就是我調用此方法的方式:
private void EnterDocument(object sender, RoutedEventArgs e)
{
List<string> myFile= new List<string>();
OpenFileDialog openFileDialog = new OpenFileDialog();
openFileDialog.Multiselect = true;
openFileDialog.Filter = "All files (*.*)|*.*|Text files (*.txt)|*.txt";
if (openFileDialog.ShowDialog() == true)
{
foreach (string filename in openFileDialog.FileNames)
{
myFile.Add(filename);
}
}
string[] myFiles= myFile.ToArray();
myDatabase = Splitter(myFiles, true, false);
}
Distinct()
將從您的IEnumerable
刪除重復項,因此請在以下操作之前調用它...
return query
.GroupBy(word => word)
.ToDictionary(g => g.Key, g => g.Count());
...將產生所有唯一單詞的列表,但計數為1。
編輯:
要解決合並所有行的問題,您可以執行以下操作:
List<string> allFilesWords = new List<string>();
foreach (var filename in file)
{
var fileQuery = File.ReadLines(filename)
.SelectMany(line => line.Split(new[] { ' '}, StringSplitOptions.RemoveEmptyEntries))
.AsParallel()
.Select(word => word.ToLower())
.Where(word => !word.All(char.IsDigit)));
allFilesWords.AddRange(fileQuery.Distinct());
}
return allFilesWords
.GroupBy(word => word)
.ToDictionary(g => g.Key, g => g.Count());
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