Merge multiple columns into one column in pyspark dataframe using python

Question

I need to merge multiple columns of a dataframe into one single column with list(or tuple) as the value for the column using pyspark in python.

Input dataframe:

+-------+-------+-------+-------+-------+
| name  |mark1  |mark2  |mark3  | Grade |
+-------+-------+-------+-------+-------+
| Jim   | 20    | 30    | 40    |  "C"  |
+-------+-------+-------+-------+-------+
| Bill  | 30    | 35    | 45    |  "A"  |
+-------+-------+-------+-------+-------+
| Kim   | 25    | 36    | 42    |  "B"  |
+-------+-------+-------+-------+-------+

Output dataframe should be

+-------+-----------------+
| name  |marks            |
+-------+-----------------+
| Jim   | [20,30,40,"C"]  |
+-------+-----------------+
| Bill  | [30,35,45,"A"]  |
+-------+-----------------+
| Kim   | [25,36,42,"B"]  |
+-------+-----------------+

Answer 1

Columns can be merged with sparks array function:

import pyspark.sql.functions as f

columns = [f.col("mark1"), ...] 

output = input.withColumn("marks", f.array(columns)).select("name", "marks")

You might need to change the type of the entries in order for the merge to be successful