keyvaluepair

问题 I have been learning Spark for several weeks, currently I am trying to group several items or people based on their connection using Spark and Hadoop in Scala. For example, I want to see how football players are connected based on their club history. My "players" rdd would be: (John, FC Sion) (Mike, FC Sion) (Bobby, PSV Eindhoven) (Hans, FC Sion) I want to have rdd like this: (John, <Mike, Hans>) (Mike, <John, Hans>) (Bobby, <>) (Hans, <Mike, John>) I plan to use map to accomplish this. val

问题 Is there any way I can convert a pair RDD back to a regular RDD? Suppose I get a local csv file, and I first load it as a regular rdd rdd = sc.textFile("$path/$csv") Then I create a pair rdd (i.e. key is the string before "," and value is the string after ",") pairRDD = rdd.map(lambda x : (x.split(",")[0], x.split(",")[1])) I store the pairRDD by using the saveAsTextFile() pairRDD.saveAsTextFile("$savePath") However, as investigated, the stored file will contain some necessary characters,

问题 I'm using a Dictionary<int, KeyValuePair<bool, int>> to hold data. From time to time I need to increment the int in the KeyValuePair , but it won't let me, because it has no setter. Is there a way to increment it? Code sample: Dictionary<int, KeyValuePair<bool, int>> mDictionary = new Dictionary<int, KeyValuePair<bool, int>>(); mDictionary[trapType].Value++; //Error: The property KeyValuePair<TKey, Tvalue>>.Value has no setter 回答1: Is there a way to increment it? No. KeyValuePair is immutable

问题 Closed. This question is off-topic. It is not currently accepting answers. Want to improve this question? Update the question so it's on-topic for Stack Overflow. Closed 5 years ago . I am teaching myself Java so I can program android applications and came across the need to use a key value pair, but don't know what it is. I tried looking it up but cannot find any good resources to explain it. Would anyone be able to explain this to me, or point me to a resource where I can read up on it?

问题 Is there any way to obtain a table with key/value pairs from a CLOB Json Column? The idea here is to get these values, on a dynamic way. Because the CLOB column does not always contain the same structure. I've created a function that does this, however since it literally parses the json string, when we use it in a table with many records its very slow. And by very slow I mean like 2-5 records per second, i know it's terrible. The Oracle tools (v.12c) do not provide a dynamic way to obtain the

问题 I'm trying to serialize a collection of object named TableDTO. This object contains a Name, Date and a List>. I'm trying to serialize it using Newtonsoft.Json library in C# Every things works good when i construct the object. I add the KeyValuePair like this : mylist.Add(new KeyValuePair<string, string>($"Col{compteur}", value.Value)); Then i add the list to my TableDTO TableDTO.List = mylist Then i serialize my object like this JsonConvert.SerializeObject(TableDto); And here is what i got {

问题 In java, how should I create a Map<String,String> that has unmodifiable keys, while keeping the values modifiable. I'd like to hand this Map<String,String> through an interface for someone else to add/change the Map values, but not be able to change the Map keys. The background on higher level problem is that I have list/set of variable names (with tree like structure) (represented as java String) that I'd like code on the other side of the java interface to be able to populate aliases (also

问题 I have this following list: var myList = new List<KeyValuePair<string, object>>(); And this function: public void Test(params KeyValuePair<string, object>[] list) How can I do a conversion of the list to params when using the function? Like that: Test(myList); 回答1: You method declaration KeyValuePair<string, object>[] list states that it will accept an array so you need to convert your list to array like this Test(myList.ToArray()); 回答2: Given the original question, I think it's worth

问题 I have some information that needs to be stored in internal memory. I will like to store in the form of key-value pairs the way its done in SharedPreferences. I was thinking of creating JsonObject and saving and retrieving in that way. Is there any other way that we can save the data in internal memory in the form of key-value pairs? 回答1: Th standard java way of storing Object data is to use Serialization - that is what it is there for. In Most cases implementing Serializable is fairly

问题 If I had an array as such: var myarray = []; myarray.push({ "Name": 'Adam', "Age": 33 }); myarray.push({ "Name": 'Emily', "Age": 32 }); This gives me an array where I can pull out values like myarray[0].Name which would give me "Adam". However, after this array is built, how can I add an "address" field with a value of "somewhere street" into the array at position [0], so that my fields in that object at position zero are now Name , Age , and Address with corresponding values? I was thinking