Reading parquet files from multiple directories in Pyspark

Question

I need to read parquet files from multiple paths that are not parent or child directories.

for example,

dir1 ---
       |
       ------- dir1_1
       |
       ------- dir1_2
dir2 ---
       |
       ------- dir2_1
       |
       ------- dir2_2

sqlContext.read.parquet(dir1) reads parquet files from dir1_1 and dir1_2

Right now I'm reading each dir and merging dataframes using "unionAll". Is there a way to read parquet files from dir1_2 and dir2_1 without using unionAll or is there any fancy way using unionAll

Thanks

Answer 1

A little late but I found this while I was searching and it may help someone else...

You might also try unpacking the argument list to spark.read.parquet()

paths=['foo','bar']
df=spark.read.parquet(*paths)

This is convenient if you want to pass a few blobs into the path argument:

basePath='s3://bucket/'
paths=['s3://bucket/partition_value1=*/partition_value2=2017-04-*',
       's3://bucket/partition_value1=*/partition_value2=2017-05-*'
      ]
df=spark.read.option("basePath",basePath).parquet(*paths)

This is cool cause you don't need to list all the files in the basePath, and you still get partition inference.