[英]How to iterate through an Iterator of Rows
我想迭代我的迭代器的前幾行,我正在嘗試像下面這樣迭代所有文件:
Dataset<Row> DF = spark.read().format("csv").load("longfile.csv");
Iterator<Row> iter = DF.toLocalIterator();
while (iter.hasNext()) { // i want a condition here to iterate only over the 20 first lines of my CSV
Row item = iter.next();
System.out.println(item);
}
我的問題是如何將迭代限制為僅 20 次? 謝謝
我建議使用 int 計數並在計數完成時中斷:
Dataset<Row> DF = spark.read().format("csv").load("longfile.csv");
Iterator<Row> iter = DF.toLocalIterator();
int count = 0;
while (iter.hasNext()) { // i want a condition here to iterate only over the 20 first lines of my CSV
count++;
Row item = iter.next();
System.out.println(item);
if(count > 20) break;
}
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