how to take value for same answered more than once and need to create each value one column - pyspark

Question

I have data like below, want to take data for same id from one column and put each answer in different new columns respectively
actual
ID Brandid
1 234
1 122
1 134
2 122
3 234
3 122
Excpected
ID BRANDID_1 BRANDID_2 BRANDID_3
1 234 122 134
2 122 - -
3 234 122 -

Answer 1

You can use pivot after a groupBy, but first you can create a column with the future column name using row_number to get monotically number per ID over a Window. Here is one way:
import pyspark.sql.functions as F
from pyspark.sql.window import Window
# create the window on ID and as you need orderBy after,
# you can use a constant to keep the original order do F.lit(1)
w = Window.partitionBy('ID').orderBy(F.lit(1))
# create the column with future columns name to pivot on
pv_df = (df.withColumn('pv', F.concat(F.lit('Brandid_'), F.row_number().over(w).cast('string')))
# groupby the ID and pivot on the created column
.groupBy('ID').pivot('pv')
# in aggregation, you need a function so we use first
.agg(F.first('Brandid')))
and you get
pv_df.show()
+---+---------+---------+---------+
| ID|Brandid_1|Brandid_2|Brandid_3|
+---+---------+---------+---------+
| 1| 234| 122| 134|
| 3| 234| 122| null|
| 2| 122| null| null|
+---+---------+---------+---------+
EDIT: to get the column in order as OP requested, you can use lpad, first define the length for number you want:
nb_pad = 3
and replace in the above method F.concat(F.lit('Brandid_'), F.row_number().over(w).cast('string')) by
F.concat(F.lit('Brandid_'), F.lpad(F.row_number().over(w).cast('string'), nb_pad, "0"))
and if you don't know how many "0" you need to add (here it was number of length of 3 overall), then you can get this value by
nb_val = len(str(sdf.groupBy('ID').count().select(F.max('count')).collect()[0][0]))