Question

我有一个Iterable Object。要将IntWriter转换为int，我们可以使用get（）方法。有一种方法可以检索Iterable Intwriter对象的第一个值。我试过

Iterator<IntWritable> values;
values.get(0).get() //To retrieve the first value.

Answer 1

你在找这个吗？

Iterator<IntWriteable> itr = iterable.iterator();
 while (itr.hasNext()) {
   System.out.println(itr.next().get());
   break;
 }

Answer 2

使用番石榴：

Iterable<IntWritable> iterable = ...;
int first = Iterables.get(iterable, 0).get();

或Java8：

int value = StreamSupport.stream(iterable.spliterator(), false).findFirst().get().get();

Answer 3

def toNumbers(sep):
    changeNum = [float(x) for x in sep]
    return changeNum

def sumlist(sep):
    total = 0
    sum(pls)
    average = sum(pls)/len(sep)
    print ("Your average is: ", average)

def main():
    file = open('grades.txt','r')
    for read in file:
        sep = read.split(",")
        sep = toNumbers(sep)
        sumlist(sep)

main()

Hadoop IntWritable Iterable按索引检索值？

3 个答案: