#Function
In PySpark, the concat_ws() function is used to concatenate multiple columns or strings into a single string, with a specified delimiter between them.

Syntax: -

from pyspark.sql.functions import concat_ws

concat_ws(delimiter, *cols)

Example 1: Concatenate two columns with a space separator

Assume you have a DataFrame with the columns First_Name and Last_Name.

from pyspark.sql.functions import concat_ws, col

# Concatenate First_Name and Last_Name with a space separator
df1 = df.withColumn("Full_Name", concat_ws(" ", col("First_Name"), col("Last_Name")))

df1.show()
Feature concat concat_ws
Separator No separator is used. Requires a separator.
Input Columns or literals only. Separator + columns/literals.
Use Case Merge values directly. Merge values with a delimiter.