[SPARK-7506] pyspark.sql.types.StructType.fromJson() is incorrectly named

• Type: Sub-task
• Status: Closed
• Priority: Minor
• Resolution: Won't Fix
• Affects Version/s: 1.3.0, 1.3.1
• Component/s: PySpark, SQL
• Sprint: Spark 1.5 doc/QA sprint
• Assignee: Unassigned
• Reporter: Nicholas Chammas
• Created: 09/May/15 17:52
• Updated: 11/May/16 18:51
• Resolved: 24/Aug/15 21:06

Description

>>> json_rdd = sqlContext.jsonRDD(sc.parallelize(['{"name": "Nick"}']))
>>> json_rdd.schema
StructType(List(StructField(name,StringType,true)))
>>> type(json_rdd.schema)
<class 'pyspark.sql.types.StructType'>
>>> json_rdd.schema.json()
'{"fields":[{"metadata":{},"name":"name","nullable":true,"type":"string"}],"type":"struct"}'
>>> pyspark.sql.types.StructType.fromJson(json_rdd.schema.json())
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/Applications/apache-spark/spark-1.3.1-bin-hadoop2.4/python/pyspark/sql/types.py", line 346, in fromJson
    return StructType([StructField.fromJson(f) for f in json["fields"]])
TypeError: string indices must be integers, not str
>>> import json
>>> pyspark.sql.types.StructType.fromJson(json.loads(json_rdd.schema.json()))
StructType(List(StructField(name,StringType,true)))
>>>

So fromJson() doesn't actually expect JSON, which is a string. It expects a dictionary.

This method should probably be renamed.