logo
down
shadow

how to iterate a list to create to Map?


how to iterate a list to create to Map?

By : Nkwoji Obinna
Date : November 22 2020, 04:01 AM
I wish this help you If you really need to iterate only once and build map's on fly, you can do it with foldLeft:
code :
val (indexedShade, indexedQuantity) = myTextFile
  .foldLeft((Map.empty[String, Color], Map.empty[String, Color]))((acc, cur) => 
    (acc._1 + (cur.toShade -> cur), acc._2 + (cur.toQuantity -> cur)))


Share : facebook icon twitter icon
Dynamically create loops to iterate over a List of List<String>'s

Dynamically create loops to iterate over a List of List<String>'s


By : vmk
Date : March 29 2020, 07:55 AM
Any of those help I have a List of List's which I get from a external API method call: , This code works for me:
code :
public class Test
{  

    public static void generate(LinkedList<LinkedList<String>> outerList, String outPut) {
        LinkedList<String> list = outerList.get(0);

        for(String str : list) {
            LinkedList<LinkedList<String>> newOuter = new LinkedList<LinkedList<String>>(outerList);
            newOuter.remove(list);

            if(outerList.size() > 1) {
                generate(newOuter, outPut+str);
             } else {
               System.out.println(outPut+str);
             }
        }
    }

    public static void main(String[] args) 
    {
        LinkedList<LinkedList<String>> outerList = new LinkedList<LinkedList<String>>();

        LinkedList<String> list1 = new LinkedList<String>();
        LinkedList<String> list2 = new LinkedList<String>();

        list1.add("A");
        list1.add("B");

        list2.add("C");
        list2.add("D");

        outerList.add(list1);
        outerList.add(list2);

        Test.generate(outerList, "");
    }      
}
How to iterate over list and remove the matched items to create a new list

How to iterate over list and remove the matched items to create a new list


By : Manjunatha Govindapp
Date : March 29 2020, 07:55 AM
Hope that helps You can use Collection#groupBy to create a map with an entry for each unique file name. You can then use Map#collect to iterate over the contents of this map and create the list you want. The map's values will be a list of instances of File, so Collection#max will let you search for the one with the highest revision number.
code :
class File {
    String name
    int type
    int revision

    String toString() { "File(name: $name; type: $type; revision: $revision)" }
}

final files = [
    new File(name: 'foo', type: 0, revision: 0),
    new File(name: 'bar', type: 0, revision: 0),
    new File(name: 'bar', type: 0, revision: 1),
    new File(name: 'baz', type: 0, revision: 0),
    new File(name: 'baz', type: 0, revision: 1),
    new File(name: 'baz', type: 1, revision: 1),
]

final result = files.groupBy { it.name }
             . collect { name, revisions -> revisions.max { it.revision } }
How to create iterate through a large list of list in python efficiently?

How to create iterate through a large list of list in python efficiently?


By : Ðjąłal ßaɃia
Date : March 29 2020, 07:55 AM
it should still fix some issue Converting a dictionary of dictionaries into a numpy or scipy array is, as you are experiencing, not too much fun. If you know all_features and all_labels before hand, you are probably better off using a scipy sparse COO matrix from the start to keep your counts.
Whether that is possible or not, you will want to keep your lists of features and labels in sorted order, to speed up look ups. So I am going to assume that the following doesn't change either array:
code :
all_features = np.array(all_features)
all_labels = np.array(all_labels)
all_features.sort()
all_labels.sort()
labels = np.fromiter(data.iterkeys(), all_labels.dtype, len(data))
label_idx = np.searchsorted(all_labels, labels)
label_features = np.fromiter((len(c) for c in data.iteritems()), np.intp,
                             len(data))
indptr = np.concatenate(([0], np.cumsum(label_features)))
nnz = indptr[-1]
import itertools
features_it = itertools.chain(*(c.iterkeys() for c in data.itervalues()))
features = np.fromiter(features_it, all_features.dtype, nnz)
feature_idx = np.searchsorted(all_features, features)
counts_it = itertools.chain(*(c.itervalues() for c in data.itervalues()))
counts = np.fromiter(counts_it, np.intp, nnz)
sps_data = csr_matrix((counts, feature_idx, indptr),
                      shape=(len(all_labels), len(all_features)))
sps_data = sps_data[np.argsort(label_idx)]
>>> sps_data.A
array([[  1,  45,   0],
       [  0,   1, 212]], dtype=int64)
>>> all_labels
array(['x', 'y'], 
      dtype='<S1')
>>> all_features
array(['a', 'b', 'c'], 
      dtype='<S1')
How to create a new list each time I iterate through a different list, giving the new list a name that contains the elem

How to create a new list each time I iterate through a different list, giving the new list a name that contains the elem


By : Nick C.
Date : March 29 2020, 07:55 AM
will be helpful for those in need Typically you would not "name" the elements of the series as you are trying to do, but rather "number" them. This is a good use case for a dict. Like this:
code :
def calculate_returns(trading_day):
    returns = {}
    for i in (1,2,5,10,30):
        returns[i] = random.random()

    return returns
How to iterate through a double linked list and create a new list to a specific value?

How to iterate through a double linked list and create a new list to a specific value?


By : Sam
Date : March 29 2020, 07:55 AM
fixed the issue. Will look into that further The ClassCastException is because start is defined to be a Node and the following code casts a Node object to a T object, which is a runtime error.
code :
b.add((T) start); //ClassCastException
b.add(start.data)
Related Posts Related Posts :
  • Using keep-left/right combinator is not working with result converter
  • How to write a doobie transaction when there's an IO stuck in the middle
  • Spark , Scala: How to remove empty lines either from Rdd or from dataframe?
  • How to convert a specific function to a udf function in apache spark with scala?
  • dataframe spark scala take the (MAX-MIN) for each group
  • Generate single case class from Seq of case classes
  • Sequential Dynamic filters on the same Spark Dataframe Column in Scala Spark
  • Scala Named method arguments cannot resolve symbol
  • ScalaTest: treat Instants as equal when in the same millisecond
  • Debugging a filter operation in scala through `in-code variable inspection`
  • why it raise a error when rdd use sortby with ordering
  • Scala Future.find
  • Functional Programming: Get new Map from existing Map with changed value
  • What are the uses of implicits and How to use them in scala?
  • CPS style for linked-list style function calls
  • need help in finding sbt assembly
  • how to cast a spark row(StructType) to scala case class
  • Subtract days from a date in the form of a string
  • How to find common elements among two array columns?
  • How to read multiline json with root element in Spark Scala?
  • Scala - why cannot use trait from object
  • Change metastore URI in Spark
  • Evolution of kafka-streams topology in production
  • How to regroup several files into one?
  • When to use "sbt assembly" and "sbt compile && sbt package"?
  • Where is the implicit value for parameter P: cats.Parallel[cats.effect.IO,F]
  • functional programming: Get list of data from nested loop
  • Scala, generic tuple
  • How to remove found :AnyVal required :Double in scala ?
  • Hellinger Distance in Scala
  • Scala chaining functions when Some without explicit checks
  • How to head DataFrame with Map[String,Long] column and preserve types?
  • How to work Supervision strategy after recover at non-linear graphs in Akka Streams
  • Spark streaming from kafka topic using scala
  • Scala concatenate Column of Array[String] into single Array[String]
  • How to find a string in a list of case class
  • Why would trait's val be evaluated if it is overridden in class?
  • SBT confused about Scala types
  • Scala Cats: How do I convert a List[ValidatedNel[E, A]] to Ior[NonEmptyList[E], List[A]]?
  • Is there an elegant way in Scala to define an asynchronous API based on a synchronous one?
  • Slick - How to insert into table with no primaryKeys
  • how to convert string to int - 0 when string is empty
  • Retrieving list of objects from application.conf
  • Cats Effect IO: Compose IO with Scala collections
  • Scala foldLeft while some conditions are true
  • Alpakka kafka vs Kafka streams
  • What is the proper way to compute graph diameter in GraphX
  • Scala: Chaining futures, returning the first
  • Akka. How to set a pem certificate in a https request
  • Flink: Access Key in RichMapFunction applied on KeyedStream to handle stream keyed by Option
  • Usage of state in updateState method (Persistent Actor)
  • Scala 2.8 - Potential problem with named arguments
  • "using" function
  • shadow
    Privacy Policy - Terms - Contact Us © bighow.org