Pyspark: Convert list to list of lists

In a pyspark dataframe, I have a column which has list values, for example: [1,2,3,4,5,6,7,8]

I would like to convert the above as [[1,2,3,4] , [5,6,7,8]] given 4 for every column value.

Please let me know, how can I achieve this.

Thanks for your help in advance.

>Solution :

You can use transform function as shown below:

df = spark.createDataFrame([([1, 2, 3, 4, 5, 6, 7, 8],)], ['values'])

df.selectExpr("transform(sequence(1, size(values), 4), v-> slice(values, v, 4)) as values")\
    .show(truncate=False)

+----------------------------+
|values                      |
+----------------------------+
|[[1, 2, 3, 4], [5, 6, 7, 8]]|
+----------------------------+