[英]C# Distinct in LINQ query
更改一些代码后,我遇到了问题。 我的想法是这样的:我正在计算文档中的单词数,但是每个文档仅包含一个单词的一个副本,例如:
文档1 = Smith Smith Smith Smith Smith => Smith x1
文档2 = Smith Alan Alan => Smith x1,Alan x1
文档3 = John John => John x1
但铁匠的总人数应:
史密斯(Smith)x2(在3个文档中有2个),艾伦(Alan)x1(3个文档中有1个),约翰(x1)(3个文档中有1个)
我认为在我有一个单独的distinct方法之前(它计算所有单词,如果distinct = false
),现在它只产生1
。
之前的代码:
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());
}
应该对其进行更改,以便它返回字典,但是在制作应用的过程中,将其更改为以下代码:
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());
}
还要注意query = file.Distinct();
仅返回文档名称。 因此,必须有所不同。
@edit这就是我调用此方法的方式:
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()
将从您的IEnumerable
删除重复项,因此请在以下操作之前调用它...
return query
.GroupBy(word => word)
.ToDictionary(g => g.Key, g => g.Count());
...将产生所有唯一单词的列表,但计数为1。
编辑:
要解决合并所有行的问题,您可以执行以下操作:
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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