Extract value from cloudant IBM Bluemix NoSQL Database - pyspark

Question

How to Extract value from Cloudant IBM Bluemix NoSQL Database stored in JSON format?
I tried this code
def readDataFrameFromCloudant(host,user,pw,database):
cloudantdata=spark.read.format("com.cloudant.spark"). \
option("cloudant.host",host). \
option("cloudant.username", user). \
option("cloudant.password", pw). \
load(database)
cloudantdata.createOrReplaceTempView("washing")
spark.sql("SELECT * from washing").show()
return cloudantdata
hostname = ""
user = ""
pw = ""
database = "database"
cloudantdata=readDataFrameFromCloudant(hostname, user, pw, database)
It is stored in this format
{
"_id": "31c24a382f3e4d333421fc89ada5361e",
"_rev": "1-8ba1be454fed5b48fa493e9fe97bedae",
"d": {
"count": 9,
"hardness": 72,
"temperature": 85,
"flowrate": 11,
"fluidlevel": "acceptable",
"ts": 1502677759234
}
}
I want this result
Expected
Actual Outcome

Answer 1

Create a dummy dataset for reproducing the issue:
cloudantdata = spark.read.json(sc.parallelize(["""
{
"_id": "31c24a382f3e4d333421fc89ada5361e",
"_rev": "1-8ba1be454fed5b48fa493e9fe97bedae",
"d": {
"count": 9,
"hardness": 72,
"temperature": 85,
"flowrate": 11,
"fluidlevel": "acceptable",
"ts": 1502677759234
}
}
"""]))
cloudantdata.take(1)
Returns:
[Row(_id='31c24a382f3e4d333421fc89ada5361e', _rev='1-8ba1be454fed5b48fa493e9fe97bedae', d=Row(count=9, flowrate=11, fluidlevel='acceptable', hardness=72, temperature=85, ts=1502677759234))]
Now flatten:
flat_df = cloudantdata.select("_id", "_rev", "d.*")
flat_df.take(1)
Returns:
[Row(_id='31c24a382f3e4d333421fc89ada5361e', _rev='1-8ba1be454fed5b48fa493e9fe97bedae', count=9, flowrate=11, fluidlevel='acceptable', hardness=72, temperature=85, ts=1502677759234)]
I tested this code with an IBM Data Science Experience notebook using Python 3.5 (Experimental) with Spark 2.0
This answer is based on: https://stackoverflow.com/a/45694796/1033422