无法使用 Databricks 将 Apache Spark parquet 文件保存到 csv

Question

I'm trying save/convert a parquet file to csv on Apache Spark with Databricks but not having much luck.

The following code successfully writes to a folder called tempDelta:

df.coalesce(1).write.format("parquet").mode("overwrite").option("header","true").save(saveloc+"/tempDelta")

I then would like to convert the parquet file to csv as follows:

df.coalesce(1).write.format("parquet").mode("overwrite").option("header","true").save(saveloc+"/tempDelta").csv(saveloc+"/tempDelta")


AttributeError                            Traceback (most recent call last)
<command-2887017733757862> in <module>
----> 1 df.coalesce(1).write.format("parquet").mode("overwrite").option("header","true").save(saveloc+"/tempDelta").csv(saveloc+"/tempDelta")

AttributeError: 'NoneType' object has no attribute 'csv'

I have also tried the following after writing to the location:

df.write.option("header","true").csv(saveloc+"/tempDelta2")

But it get the error:

A transaction log for Databricks Delta was found at `/CURATED/F1Area/F1Domain/final/_delta_log`,
but you are trying to write to `/CURATED/F1Area/F1Domain/final/tempDelta2` using format("csv"). You must use
'format("delta")' when reading and writing to a delta table.

And when I try to save as a csv to folder that isn't a delta folder I get the following error:

df.write.option("header","true").csv("testfolder")


AnalysisException: CSV data source does not support struct data type.

Can someone let me know the best way of saving / converting from parquet to csv with Databricks

Answer 1

You can use either of the below 2 options

1. df.write.option("header",true).csv(path)

2. df.write.format("csv").save(path)

Note: You cant mention format as parquet and use.csv function at once.