[jira] [Created] (SPARK-27609) [Documentation Issue?] from_json expects values of options dictionary to be

["Zachary Jablons (JIRA)" <ji...@apache.org>]

Zachary Jablons created SPARK-27609:
---------------------------------------

             Summary: [Documentation Issue?] from_json expects values of options dictionary to be 
                 Key: SPARK-27609
                 URL: https://issues.apache.org/jira/browse/SPARK-27609
             Project: Spark
          Issue Type: Bug
          Components: PySpark
    Affects Versions: 2.2.1
         Environment: I've found this issue on an AWS Glue development endpoint which is running Spark 2.2.1 and being given jobs through a SparkMagic Python 2 kernel, running through livy and all that. I don't know how much of that is important for reproduction, and can get more details if needed. 
            Reporter: Zachary Jablons


When reading a column of a DataFrame that consists of serialized JSON, one of the options for inferring the schema and then parsing the JSON is to do a two step process consisting of:

 

{{#this results in a new dataframe where the top-level keys of the JSON # are columns}}

{{df_parsed_direct = spark.read.json(df.rdd.map(lambda row: row.json_col))}}

{{# this does that while preserving the rest of df}}
 {{schema = df_parsed_direct.schema}}
 {{df_parsed = df.withColumn('parsed', from_json(df.json_col, schema)}}

When I do this, I sometimes find myself passing in options. My understanding is, from the documentation [here|http://spark.apache.org/docs/2.1.0/api/python/pyspark.sql.html#pyspark.sql.functions.from_json], that the nature of these options passed should be the same whether I do

{{spark.read.option('option',value)}}

or

{{from_json(df.json_col, schema, options=\{'option':value})}}

 

However, I've found that the latter expects value to be a string representation of the value that can be decoded by JSON. So, for example options=\{'multiLine':True} fails with 

{{java.lang.ClassCastException: java.lang.Boolean cannot be cast to java.lang.String}}

whereas options=\{'multiLine':'true'} works just fine. 

Notably, providing spark.read.option('multiLine',True) works fine!

 

The code for reproducing this issue as well as the stacktrace from hitting it are provided in [this gist|https://gist.github.com/zmjjmz/0af5cf9b059b4969951e825565e266aa]. 

 

I also noticed that from_json doesn't complain if you give it a garbage option key – but that seems separate.



--
This message was sent by Atlassian JIRA
(v7.6.3#76005)

---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@spark.apache.org
For additional commands, e-mail: issues-help@spark.apache.org