SPRKPY1076

Parameters in pyspark.sql.readwriter.DataFrameReader

Message: Parameters in pyspark.sql.readwriter.DataFrameReader methods are not supported. This applies to CSV, JSON and PARQUET methods.

Category: Warning.

Description

For the CSV, JSON and PARQUET methods on the pyspark.sql.readwriter.DataFrameReader object, the tool will analyze the parameters and add a transformation according to each case:

• All the parameters match their equivalent name in Snowpark: in this case, the tool will transform the parameter into a .option() call. For this case, the parameter won't add this EWI.

• Some parameters do not match the equivalent in Snowpark: in this case, the tool will add this EWI with the parameter information and remove it from the method call.

List of equivalences:

• Equivalences for CSV:

Spark keys	Snowpark Equivalences
sep	FIELD_DELIMITER
header	PARSE_HEADER
lineSep	RECORD_DELIMITER
pathGlobFilter	PATTERN
quote	FIELD_OPTIONALLY_ENCLOSED_BY
nullValue	NULL_IF
dateFormat	DATE_FORMAT
timestampFormat	TIMESTAMP_FORMAT
inferSchema	INFER_SCHEMA
delimiter	FIELD_DELIMITER

• Equivalences for JSON:

Spark keys	Snowpark Equivalences
dateFormat	DATE_FORMAT
timestampFormat	TIMESTAMP_FORMAT
pathGlobFilter	PATTERN

• Equivalences for PARQUET:

Spark keys	Snowpark Equivalences
pathGlobFilter	PATTERN

Scenarios

Scenario 1

Input

For CVS here are some examples:

from pyspark.sql import SparkSession

spark = SparkSession.builder.appName('myapp').getOrCreate()

spark.read.csv("path3", None,None,None,None,None,None,True).show()

Output

In the converted code the parameters are added as individual options to the cvs function

from snowflake.snowpark import Session

spark = Session.builder.app_name('myapp', True).getOrCreate()
spark.update_query_tag({"origin":"sf_sit","name":"sma","version":{"major":0,"minor":0,"patch":0},"attributes":{"language":"Python"}})

#EWI: SPRKPY1076 => Some of the included parameters are not supported in the csv function, the supported ones will be added into a option method.
spark.read.option("FIELD_DELIMITER", None).option("PARSE_HEADER", True).option("FIELD_OPTIONALLY_ENCLOSED_BY", None).csv("path3").show()

Scenario 2

Input

For JSON here are some example:

from pyspark.sql import SparkSession
spark = SparkSession.builder.appName('myapp').getOrCreate()
spark.read.json("/myPath/jsonFile/", dateFormat='YYYY/MM/DD').show()

Output

In the converted code the parameters are added as individual options to the json function

from snowflake.snowpark import Session
spark = Session.builder.app_name('myapp', True).getOrCreate()
#EWI: SPRKPY1076 => Some of the included parameters are not supported in the json function, the supported ones will be added into a option method.

spark.read.option("DATE_FORMAT", 'YYYY/MM/DD').json("/myPath/jsonFile/").show()

Scenario 3

Input

For PARQUET here are some examples:

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

spark.read.parquet("/path/to/my/file.parquet", pathGlobFilter="*.parquet").show()

Output

In the converted code the parameters are added as individual options to the parquet function

from snowflake.snowpark import Session

spark = Session.builder.app_name('myapp', True).getOrCreate()
spark.update_query_tag({"origin":"sf_sit","name":"sma","version":{"major":0,"minor":0,"patch":0},"attributes":{"language":"Python"}})

#EWI: SPRKPY1076 => Some of the included parameters are not supported in the parquet function, the supported ones will be added into a option method.
#EWI: SPRKPY1029 => The parquet function require adjustments, in Snowpark the parquet files needs to be located in an stage. See the documentation for more info.

spark.read.option("PATTERN", "*.parquet").parquet("/path/to/my/file.parquet")

Additional recommendations

• When non-equivalent parameters are present, it is recommended to check the behavior after the transformation.

• Also the documentation could be useful to find a better fit:

  • Options documentation for CSV:

    • PySpark CSV Options.
    • Snowpark CSV Options.
  • Options documentation for JSON:

    • PySpark JSON Options.
    • Snowpark JSON Options.
  • Options documentation for PARQUET:

    • Pyspark PARQUET options.
    • SnowPark PARQUET options..
• For more support, you can email us at [e-mail] or post an issue in the SMA.