I've successfully create a row_number()
partitionBy
by in Spark using Window, but would like to sort this by descending, instead of the default ascending. Here is my working code:
from pyspark import HiveContext
from pyspark.sql.types import *
from pyspark.sql import Row, functions as F
from pyspark.sql.window import Window
data_cooccur.select("driver", "also_item", "unit_count",
F.rowNumber().over(Window.partitionBy("driver").orderBy("unit_count")).alias("rowNum")).show()
That gives me this result:
+------+---------+----------+------+
|driver|also_item|unit_count|rowNum|
+------+---------+----------+------+
| s10| s11| 1| 1|
| s10| s13| 1| 2|
| s10| s17| 1| 3|
And here I add the desc() to order descending:
data_cooccur.select("driver", "also_item", "unit_count", F.rowNumber().over(Window.partitionBy("driver").orderBy("unit_count").desc()).alias("rowNum")).show()
And get this error:
AttributeError: 'WindowSpec' object has no attribute 'desc'
What am I doing wrong here?
desc
should be applied on a column not a window definition. You can use either a method on a column:
from pyspark.sql.functions import col, row_number
from pyspark.sql.window import Window
F.row_number().over(
Window.partitionBy("driver").orderBy(col("unit_count").desc())
)
or a standalone function:
from pyspark.sql.functions import desc
from pyspark.sql.window import Window
F.row_number().over(
Window.partitionBy("driver").orderBy(desc("unit_count"))
)