DataFrame reduce by - pyspark

Need help on ... converting multiple rows into single row by keys. group by advise appreciated. Using pyspark Version:2
l = (1,1,'', 'add1' ),
(1,1,'name1', ''),
(1,2,'', 'add2'),
(1,2,'name2', ''),
(2,1,'', 'add21'),
(2,1,'name21', ''),
(2,2,'', 'add22'),
(2,2,'name22', '')
df = sqlContext.createDataFrame(l, ['Key1', 'Key2','Name', 'Address'])
df.show()
+----+----+------+-------+
|Key1|Key2| Name|Address|
+----+----+------+-------+
| 1| 1| | add1|
| 1| 1| name1| |
| 1| 2| | add2|
| 1| 2| name2| |
| 2| 1| | add21|
| 2| 1|name21| |
| 2| 2| | add22|
| 2| 2|name22| |
+----+----+------+-------+
I am stuck looking for output like
+----+----+------+-------+
|Key1|Key2| Name|Address|
+----+----+------+-------+
| 1| 1| name1 | add1|
| 1| 2| name2 | add2|
| 2| 1| name21| add21|
| 2| 2| name22| add22|
+----+----+------+-------+

Group by Key1 and Key2, and take the maximum value from Name and Address:
import pyspark.sql.functions as F
df.groupBy(['Key1', 'Key2']).agg(
F.max(df.Name).alias('Name'),
F.max(df.Address).alias('Address')
).show()
+----+----+------+-------+
|Key1|Key2| Name|Address|
+----+----+------+-------+
| 1| 1| name1| add1|
| 2| 2|name22| add22|
| 1| 2| name2| add2|
| 2| 1|name21| add21|
+----+----+------+-------+

Related

Unable to get the result from the window function

+---------------+--------+
|YearsExperience| Salary|
+---------------+--------+
| 1.1| 39343.0|
| 1.3| 46205.0|
| 1.5| 37731.0|
| 2.0| 43525.0|
| 2.2| 39891.0|
| 2.9| 56642.0|
| 3.0| 60150.0|
| 3.2| 54445.0|
| 3.2| 64445.0|
| 3.7| 57189.0|
| 3.9| 63218.0|
| 4.0| 55794.0|
| 4.0| 56957.0|
| 4.1| 57081.0|
| 4.5| 61111.0|
| 4.9| 67938.0|
| 5.1| 66029.0|
| 5.3| 83088.0|
| 5.9| 81363.0|
| 6.0| 93940.0|
| 6.8| 91738.0|
| 7.1| 98273.0|
| 7.9|101302.0|
| 8.2|113812.0|
| 8.7|109431.0|
| 9.0|105582.0|
| 9.5|116969.0|
| 9.6|112635.0|
| 10.3|122391.0|
| 10.5|121872.0|
+---------------+--------+
I want to find the top highest salary from the above data which is 122391.0
My Code
val top= Window.partitionBy("id").orderBy(col("Salary").desc)
val res= df1.withColumn("top", rank().over(top))
Result
+---------------+--------+---+---+
|YearsExperience| Salary| id|top|
+---------------+--------+---+---+
| 1.1| 39343.0| 0| 1|
| 1.3| 46205.0| 1| 1|
| 1.5| 37731.0| 2| 1|
| 2.0| 43525.0| 3| 1|
| 2.2| 39891.0| 4| 1|
| 2.9| 56642.0| 5| 1|
| 3.0| 60150.0| 6| 1|
| 3.2| 54445.0| 7| 1|
| 3.2| 64445.0| 8| 1|
| 3.7| 57189.0| 9| 1|
| 3.9| 63218.0| 10| 1|
| 4.0| 55794.0| 11| 1|
| 4.0| 56957.0| 12| 1|
| 4.1| 57081.0| 13| 1|
| 4.5| 61111.0| 14| 1|
| 4.9| 67938.0| 15| 1|
| 5.1| 66029.0| 16| 1|
| 5.3| 83088.0| 17| 1|
| 5.9| 81363.0| 18| 1|
| 6.0| 93940.0| 19| 1|
| 6.8| 91738.0| 20| 1|
| 7.1| 98273.0| 21| 1|
| 7.9|101302.0| 22| 1|
| 8.2|113812.0| 23| 1|
| 8.7|109431.0| 24| 1|
| 9.0|105582.0| 25| 1|
| 9.5|116969.0| 26| 1|
| 9.6|112635.0| 27| 1|
| 10.3|122391.0| 28| 1|
| 10.5|121872.0| 29| 1|
+---------------+--------+---+---+
Also I have choosed partioned by salary and orderby id.
<br>
But the result was same.
As you can see 122391 is coming just below the above but it should come in first position as i have done ascending.
Please help anybody find any things
Are you sure you need a window function here? The window you defined partitions the data by id, which I assume is unique, so each group produced by the window will only have one row. It looks like you want a window over the entire dataframe, which means you don't actually need one. If you just want to add a column with the max, you can get the max using an aggregation on your original dataframe and cross join with it:
val maxDF = df1.agg(max("salary").as("top"))
val res = df1.crossJoin(maxDF)

Pyspark combine different rows base on a column

I have a dataframe
+----------------+------------+-----+
| Sport|Total_medals|count|
+----------------+------------+-----+
| Alpine Skiing| 3| 4|
| Alpine Skiing| 2| 18|
| Alpine Skiing| 4| 1|
| Alpine Skiing| 1| 38|
| Archery| 2| 12|
| Archery| 1| 72|
| Athletics| 2| 50|
| Athletics| 1| 629|
| Athletics| 3| 8|
| Badminton| 2| 5|
| Badminton| 1| 86|
| Baseball| 1| 216|
| Basketball| 1| 287|
|Beach Volleyball| 1| 48|
| Biathlon| 4| 1|
| Biathlon| 3| 9|
| Biathlon| 1| 61|
| Biathlon| 2| 23|
| Bobsleigh| 2| 6|
| Bobsleigh| 1| 60|
+----------------+------------+-----+
Is there a way for me to combine the value of counts from multiple rows if they are from the same sport?
For example, if Sport = Alpine Skiing I would have something like this:
+----------------+-----+
| Sport|count|
+----------------+-----+
| Alpine Skiing| 61|
+----------------+-----+
where count is equal to 4+18+1+38 = 61. I would like to do this for all sports
any help would be appreciated
You need to groupby on the Sport column and then aggregate the count column with the sum() function.
Example:
import pyspark.sql.functions as F
grouped_df = df.groupby('Sport').agg(F.sum('count'))

How to count change in row values in pyspark

Logic to count the change in the row values of a given column
Input
df22 = spark.createDataFrame(
[(1, 1.0), (1,22.0), (1,22.0), (1,21.0), (1,20.0), (2, 3.0), (2,3.0),
(2, 5.0), (2, 10.0), (2,3.0), (3,11.0), (4, 11.0), (4,15.0), (1,22.0)],
("id", "v"))
+---+----+
| id| v|
+---+----+
| 1| 1.0|
| 1|22.0|
| 1|22.0|
| 1|21.0|
| 1|20.0|
| 2| 3.0|
| 2| 3.0|
| 2| 5.0|
| 2|10.0|
| 2| 3.0|
| 3|11.0|
| 4|11.0|
| 4|15.0|
+---+----+
Expect output
+---+----+---+
| id| v| c|
+---+----+---+
| 1| 1.0| 0|
| 1|22.0| 1|
| 1|22.0| 1|
| 1|21.0| 2|
| 1|20.0| 3|
| 2| 3.0| 0|
| 2| 3.0| 0|
| 2| 5.0| 1|
| 2|10.0| 2|
| 2| 3.0| 3|
| 3|11.0| 0|
| 4|11.0| 0|
| 4|15.0| 1|
+---+----+---+
Any help on this will be greatly appreciated
Thanks in advance
Ramabadran
Before adding answer, I would like to ask you ,"what you have tried ??". Please try something from your end and then seek for support in this platform. Also your question is not clear. You have not provided if you are looking for a delta capture count per 'id' or as a whole. Just giving an expected output is not going to make the question clear.
And now comes to your question , if I understood it correctly from the sample input and output,you need delta capture count per 'id'. So one way to achieve it as below
#Capture the incremented count using lag() and sum() over below mentioned window
import pyspark.sql.functions as F
from pyspark.sql.window import Window
winSpec=Window.partitionBy('id').orderBy('v') # Your Window for capturing the incremented count
df22.\
withColumn('prev',F.coalesce(F.lag('v').over(winSpec),F.col('v'))).\
withColumn('c',F.sum(F.expr("case when v-prev<>0 then 1 else 0 end")).over(winSpec)).\
drop('prev').\
orderBy('id','v').\
show()
+---+----+---+
| id| v| c|
+---+----+---+
| 1| 1.0| 0|
| 1|20.0| 1|
| 1|21.0| 2|
| 1|22.0| 3|
| 1|22.0| 3|
| 1|22.0| 3|
| 2| 3.0| 0|
| 2| 3.0| 0|
| 2| 3.0| 0|
| 2| 5.0| 1|
| 2|10.0| 2|
| 3|11.0| 0|
| 4|11.0| 0|
| 4|15.0| 1|
+---+----+---+

Scala Spark Incrementing a column based on another column in dataframe without for loops

I have a dataframe like the one below. I want a new column called cutofftype - which instead of the current monotonically increasing number should reset to 1 every time the ID column changes .
df = df.orderBy("ID","date").withColumn("cutofftype",monotonically_increasing_id()+1)
+------+---------------+----------+
| ID | date |cutofftype|
+------+---------------+----------+
| 54441| 2016-06-20| 1|
| 54441| 2016-06-27| 2|
| 54441| 2016-07-04| 3|
| 54441| 2016-07-11| 4|
| 54500| 2016-05-02| 5|
| 54500| 2016-05-09| 6|
| 54500| 2016-05-16| 7|
| 54500| 2016-05-23| 8|
| 54500| 2016-06-06| 9|
| 54500| 2016-06-13| 10|
+------+---------------+----------+
Target is this as below :
+------+---------------+----------+
| ID | date |cutofftype|
+------+---------------+----------+
| 54441| 2016-06-20| 1|
| 54441| 2016-06-27| 2|
| 54441| 2016-07-04| 3|
| 54441| 2016-07-11| 4|
| 54500| 2016-05-02| 1|
| 54500| 2016-05-09| 2|
| 54500| 2016-05-16| 3|
| 54500| 2016-05-23| 4|
| 54500| 2016-06-06| 5|
| 54500| 2016-06-13| 6|
+------+---------------+----------+
I know this can be done with for loops - i want to do it without for loops >> Is there a way out ?
Simple partition by problem. You should use the window.
import org.apache.spark.sql.expressions.Window
val w = Window.partitionBy("ID").orderBy("date")
df.withColumn("cutofftype", row_number().over(w)).show()
+-----+----------+----------+
| ID| date|cutofftype|
+-----+----------+----------+
|54500|2016-05-02| 1|
|54500|2016-05-09| 2|
|54500|2016-05-16| 3|
|54500|2016-05-23| 4|
|54500|2016-06-06| 5|
|54500|2016-06-13| 6|
|54441|2016-06-20| 1|
|54441|2016-06-27| 2|
|54441|2016-07-04| 3|
|54441|2016-07-11| 4|
+-----+----------+----------+

Pass Distinct value of one Dataframe into another Dataframe

I want to take distinct value of column from DataFrame A and Pass that into DataFrame B's explode
function to create repeat rows (DataFrameB) for each distinct value.
distinctSet = targetDf.select('utilityId').distinct())
utilisationFrequencyTable = utilisationFrequencyTable.withColumn("utilityId", psf.explode(assign_utilityId()))
Function
assign_utilityId = psf.udf(
lambda id: [x for x in id],
ArrayType(LongType()))
How to pass distinctSet values to assign_utilityId
Update
+---------+
|utilityId|
+---------+
| 101|
| 101|
| 102|
+---------+
+-----+------+--------+
|index|status|timeSlot|
+-----+------+--------+
| 0| SUN| 0|
| 0| SUN| 1|
I want to take Unique value from Dataframe 1 and create new column in dataFrame 2. Like this
+-----+------+--------+--------+
|index|status|timeSlot|utilityId
+-----+------+--------+--------+
| 0| SUN| 0|101
| 0| SUN| 1|101
| 0| SUN| 0|102
| 0| SUN| 1|102
We don't need a udf for this. I have tried with some input,please check
>>> from pyspark.sql import function as F
>>> df = spark.createDataFrame([(1,),(2,),(3,),(2,),(3,)],['col1'])
>>> df.show()
+----+
|col1|
+----+
| 1|
| 2|
| 3|
| 2|
| 3|
+----+
>>> df1 = spark.createDataFrame([(1,2),(2,3),(3,4)],['col1','col2'])
>>> df1.show()
+----+----+
|col1|col2|
+----+----+
| 1| 2|
| 2| 3|
| 3| 4|
+----+----+
>>> dist_val = df.select(F.collect_set('col1').alias('val')).first()['val']
>>> dist_val
[1, 2, 3]
>>> df1 = df1.withColumn('col3',F.array([F.lit(x) for x in dist_val]))
>>> df1.show()
+----+----+---------+
|col1|col2| col3|
+----+----+---------+
| 1| 2|[1, 2, 3]|
| 2| 3|[1, 2, 3]|
| 3| 4|[1, 2, 3]|
+----+----+---------+
>>> df1.select("*",F.explode('col3').alias('expl_col')).drop('col3').show()
+----+----+--------+
|col1|col2|expl_col|
+----+----+--------+
| 1| 2| 1|
| 1| 2| 2|
| 1| 2| 3|
| 2| 3| 1|
| 2| 3| 2|
| 2| 3| 3|
| 3| 4| 1|
| 3| 4| 2|
| 3| 4| 3|
+----+----+--------+
df = sqlContext.createDataFrame(sc.parallelize([(101,),(101,),(102,)]),['utilityId'])
df2 = sqlContext.createDataFrame(sc.parallelize([(0,'SUN',0),(0,'SUN',1)]),['index','status','timeSlot'])
rdf = df.distinct()
>>> df2.join(rdf).show()
+-----+------+--------+---------+
|index|status|timeSlot|utilityId|
+-----+------+--------+---------+
| 0| SUN| 0| 101|
| 0| SUN| 0| 102|
| 0| SUN| 1| 101|
| 0| SUN| 1| 102|
+-----+------+--------+---------+