python - pyspark and HDFS commands

Question

I would like to do some cleanup at the start of my Spark program (Pyspark). For example, I would like to delete data from previous HDFS run. In pig this can be done using commands such as

fs -copyFromLocal ....

rmf /path/to-/hdfs

or locally using sh command.

I was wondering how to do the same with Pyspark.

Answer 1

You can delete an hdfs path in PySpark without using third party dependencies as follows:

from pyspark.sql import SparkSession
# example of preparing a spark session
spark = SparkSession.builder.appName('abc').getOrCreate()
sc = spark.sparkContext
# Prepare a FileSystem manager
fs = (sc._jvm.org
      .apache.hadoop
      .fs.FileSystem
      .get(sc._jsc.hadoopConfiguration())
      )
path = "Your/hdfs/path"
# use the FileSystem manager to remove the path
fs.delete(sc._jvm.org.apache.hadoop.fs.Path(path), True)

---

To improve one step further, you can wrap the above idea into a helper function that you can re-use across jobs/packages:

from pyspark.sql import SparkSession
spark = SparkSession.builder.appName('abc').getOrCreate()

def delete_path(spark, path):
    sc = spark.sparkContext
    fs = (sc._jvm.org
          .apache.hadoop
          .fs.FileSystem
          .get(sc._jsc.hadoopConfiguration())
          )
    fs.delete(sc._jvm.org.apache.hadoop.fs.Path(path), True)

delete_path(spark, "Your/hdfs/path")