Custom Concat Columns for PySpark

custom_concat_columns.py

from pyspark.sql.functions import col, concat, lit

custom_concat = [col('appName'), lit('|'), col('platform'), lit('|'), 
                 col('carrier'), lit('|'), col('connectionType'), lit('|'), 
                 col('country'), lit('|'), col('city'), lit('|'), 
                 col('userAgent')]

# Add a new column entitled "custom_col"
union_df = union_df.withColumn('custom_col', concat(*custom_concat))