how to get the column names which have top 3 largest values for each row in Pyspark -

sample dataframe

id  a1  a2  a3  a4  a5  a6 0   5  23   4   1   4   5 1   6  43   2   2   98   43 2   3  56   3   1  23   3 3   2   2   6   3   5   2 4   5   6   7   2   7   5 

i need this....

top1 top2 top3 a2   a1   a6 a5   a2   a6 

hope helps!

from pyspark.sql.functions import col, udf, array, sort_array pyspark.sql.types import stringtype  df = sc.parallelize([(0, 5, 23, 4, 1, 4, 5),                      (1, 6, 43, 2, 2, 98, 43),                      (2, 3, 56, 3, 1, 23, 3),                      (3, 2, 2, 6, 3, 5, 2),                      (4, 5, 6, 7, 2, 7, 5)]).\     todf(["id","a1","a2","a3","a4","a5","a6"]) df_col = df.columns  df = df.\     withcolumn("top1_val", sort_array(array([col(x) x in df_col[1:]]), asc=false)[0]).\     withcolumn("top2_val", sort_array(array([col(x) x in df_col[1:]]), asc=false)[1]).\     withcolumn("top3_val", sort_array(array([col(x) x in df_col[1:]]), asc=false)[2])  def modify_values(r, max_col):     l = []     in range(len(df_col[1:])):         if r[i]== max_col:             l.append(df_col[i+1])     return l modify_values_udf = udf(modify_values, stringtype())  df1 = df.\     withcolumn("top1", modify_values_udf(array(df.columns[1:-3]), "top1_val")).\     withcolumn("top2", modify_values_udf(array(df.columns[1:-3]), "top2_val")).\     withcolumn("top3", modify_values_udf(array(df.columns[1:-3]), "top3_val")) df1.show() 

output is:

+---+---+---+---+---+---+---+--------+--------+--------+--------+--------+------------+ | id| a1| a2| a3| a4| a5| a6|top1_val|top2_val|top3_val|    top1|    top2|        top3| +---+---+---+---+---+---+---+--------+--------+--------+--------+--------+------------+ |  0|  5| 23|  4|  1|  4|  5|      23|       5|       5|    [a2]|[a1, a6]|    [a1, a6]| |  1|  6| 43|  2|  2| 98| 43|      98|      43|      43|    [a5]|[a2, a6]|    [a2, a6]| |  2|  3| 56|  3|  1| 23|  3|      56|      23|       3|    [a2]|    [a5]|[a1, a3, a6]| |  3|  2|  2|  6|  3|  5|  2|       6|       5|       3|    [a3]|    [a5]|        [a4]| |  4|  5|  6|  7|  2|  7|  5|       7|       7|       6|[a3, a5]|[a3, a5]|        [a2]| +---+---+---+---+---+---+---+--------+--------+--------+--------+--------+------------+