Java 类名:com.alibaba.alink.operator.batch.dataproc.FirstNBatchOp
Python 类名:FirstNBatchOp

功能介绍

该组件输出表的前N条数据。

参数说明

名称 中文名称 描述 类型 是否必须? 取值范围 默认值
size 采样个数 采样个数 Integer [1, +inf)

代码示例

Python 代码

  1. from pyalink.alink import *
  2. import pandas as pd
  3. useLocalEnv(1)
  4. df = pd.DataFrame([
  5. ["0,0,0"],
  6. ["0.1,0.1,0.1"],
  7. ["0.2,0.2,0.2"],
  8. ["9,9,9"],
  9. ["9.1,9.1,9.1"],
  10. ["9.2,9.2,9.2"]
  11. ])
  12. # batch source
  13. inOp = BatchOperator.fromDataframe(df, schemaStr='Y string')
  14. sampleOp = FirstNBatchOp()\
  15. .setSize(2)
  16. inOp.link(sampleOp).print()

Java 代码

  1. import org.apache.flink.types.Row;
  2. import com.alibaba.alink.operator.batch.BatchOperator;
  3. import com.alibaba.alink.operator.batch.dataproc.FirstNBatchOp;
  4. import com.alibaba.alink.operator.batch.source.MemSourceBatchOp;
  5. import org.junit.Test;
  6. import java.util.Arrays;
  7. import java.util.List;
  8. public class FirstNBatchOpTest {
  9. @Test
  10. public void testFirstNBatchOp() throws Exception {
  11. List <Row> df = Arrays.asList(
  12. Row.of("0,0,0"),
  13. Row.of("0.1,0.1,0.1"),
  14. Row.of("0.2,0.2,0.2"),
  15. Row.of("9,9,9"),
  16. Row.of("9.1,9.1,9.1"),
  17. Row.of("9.2,9.2,9.2")
  18. );
  19. BatchOperator <?> inOp = new MemSourceBatchOp(df, "Y string");
  20. BatchOperator <?> sampleOp = new FirstNBatchOp()
  21. .setSize(2);
  22. inOp.link(sampleOp).print();
  23. }
  24. }

运行结果

| Y | | —- |

| 0,0,0 |

| 0.1,0.1,0.1 |