Adding constant value column to spark dataframe

Question

I am using Spark version 2.1 in Databricks. I have a data frame named wamp to which I want to add a column named region which should take the constant value NE. However, I get an error saying NameError: name 'lit' is not defined when I run the following command:

wamp = wamp.withColumn('region', lit('NE'))

What am I doing wrong?

Answer 1

you need to import lit

either

from pyspark.sql.functions import *

will make lit available

or something like

import pyspark.sql.functions as sf
wamp = wamp.withColumn('region', sf.lit('NE'))

Answer 2

muon@ provided the correct answer above. Just adding a quick reproducible version to increase clarity.

>>> from pyspark.sql.functions import lit
>>> df = spark.createDataFrame([(1, 4, 3)], ['a', 'b', 'c'])
>>> df.show()
+---+---+---+
|  a|  b|  c|
+---+---+---+
|  1|  4|  3|
+---+---+---+

>>> df = df.withColumn("d", lit(5))
>>> df.show()
+---+---+---+---+
|  a|  b|  c|  d|
+---+---+---+---+
|  1|  4|  3|  5|
+---+---+---+---+